Patent Publication Number: US-10783227-B2

Title: Implementation of biometric authentication

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/125,267, “IMPLEMENTATION OF BIOMETRIC AUTHENTICATION,” filed Sep. 7, 2018, which claims priority to U.S. Provisional Patent Application Nos. 62/556,413, “FACE ENROLLMENT AND AUTHENTICATION,” filed Sep. 9, 2017; 62/557,130, “IMPLEMENTATION OF BIOMETRIC AUTHENTICATION,” filed Sep. 11, 2017; 62/581,025, “IMPLEMENTATION OF BIOMETRIC AUTHENTICATION,” filed Nov. 2, 2017; and 62/679,955, “IMPLEMENTATION OF BIOMETRIC AUTHENTICATION,” filed Jun. 3, 2018. All of these applications are incorporated by reference herein in their entirety. 
    
    
     FIELD 
     The present disclosure relates generally to biometric authentication, and more specifically to interfaces and techniques for enrollment and authentication of biometric features. 
     BACKGROUND 
     Biometric authentication, for instance of a face, iris, or fingerprint, using electronic devices is a convenient and efficient method of authenticating users of the electronic devices. Biometric authentication allows a device to quickly and easily verify the identity of any number of users. 
     BRIEF SUMMARY 
     Some techniques for implementing biometric authentication using electronic devices, however, are generally cumbersome. For example, some existing techniques, such as those directed to facial recognition, require a user to almost perfectly align a biometric feature in a same manner during both enrollment and each iteration of authentication. Deviation from the alignment of the biometric feature often results in a false negative result. As a result, a user is, optionally, required to unnecessarily perform multiple iterations of biometric authentication, or is, optionally, discouraged from using the biometric authentication altogether. As another example, some existing techniques rely solely on a two-dimensional representation of a biometric feature. As a result, authentication of a user is, optionally, limited by virtue of a failure to analyze one or more three-dimensional characteristics of the biometric feature and also optionally requires a user to unnecessarily perform additional iterations of biometric authentication. In view of the foregoing drawbacks, existing techniques require more time than necessary, wasting both user time and device energy. This latter consideration is particularly significant in the operation of battery-operated devices. 
     Accordingly, the present technique provides electronic devices with faster, more efficient methods and interfaces for implementing biometric authentication. Such methods and interfaces optionally complement or replace other methods for implementing biometric authentication. Such methods and interfaces reduce the cognitive burden on a user and produce a more efficient human-machine interface. For battery-operated computing devices, such methods and interfaces conserve power and increase the time between battery charges. Such methods and interfaces also reduce the number of unnecessary, extraneous, or repetitive input required at computing devices, such as smartphones and smartwatches. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with one or more input devices, one or more biometric sensors, and a display: displaying, on the display, a first user interface; while displaying the first user interface, detecting an occurrence of a condition that corresponds to introduction of a biometric enrollment process for enrolling a biometric feature; in response to detecting the occurrence of the condition that corresponds to introduction of the biometric enrollment process, displaying a biometric enrollment introduction interface, wherein displaying the biometric enrollment introduction interface includes concurrently displaying: a representation of a simulation of the biometric feature; and a simulated progress indicator; while displaying the biometric enrollment introduction interface, displaying an instructional animation that includes displaying movement of the representation of the simulation of the biometric feature and incremental advancement of the simulated progress indicator; after displaying at least a portion of the instructional animation, detecting an occurrence of a condition that corresponds to initiation of the biometric enrollment process; and in response to detecting the occurrence of the condition that corresponds to initiation of the biometric enrollment process: displaying a progress indicator that corresponds to the simulated progress indicator; and displaying, at a location that was previously occupied by the representation of the simulation of the biometric feature in the biometric enrollment introduction interface, a representation of the biometric feature of the user as determined by the one or more biometric sensors of the device. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more input devices, one or more biometric sensors, and a display, the one or more programs including instructions for: displaying, on the display, a first user interface; while displaying the first user interface, detecting an occurrence of a condition that corresponds to introduction of a biometric enrollment process for enrolling a biometric feature; in response to detecting the occurrence of the condition that corresponds to introduction of the biometric enrollment process, displaying a biometric enrollment introduction interface, wherein displaying the biometric enrollment introduction interface includes concurrently displaying: a representation of a simulation of the biometric feature; and a simulated progress indicator; while displaying the biometric enrollment introduction interface, displaying an instructional animation that includes displaying movement of the representation of the simulation of the biometric feature and incremental advancement of the simulated progress indicator; after displaying at least a portion of the instructional animation, detecting an occurrence of a condition that corresponds to initiation of the biometric enrollment process; and in response to detecting the occurrence of the condition that corresponds to initiation of the biometric enrollment process: displaying a progress indicator that corresponds to the simulated progress indicator; and displaying, at a location that was previously occupied by the representation of the simulation of the biometric feature in the biometric enrollment introduction interface, a representation of the biometric feature of the user as determined by the one or more biometric sensors of the device. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more input devices, one or more biometric sensors, and a display, the one or more programs including instructions for: displaying, on the display, a first user interface; while displaying the first user interface, detecting an occurrence of a condition that corresponds to introduction of a biometric enrollment process for enrolling a biometric feature; in response to detecting the occurrence of the condition that corresponds to introduction of the biometric enrollment process, displaying a biometric enrollment introduction interface, wherein displaying the biometric enrollment introduction interface includes concurrently displaying: a representation of a simulation of the biometric feature; and a simulated progress indicator; while displaying the biometric enrollment introduction interface, displaying an instructional animation that includes displaying movement of the representation of the simulation of the biometric feature and incremental advancement of the simulated progress indicator; after displaying at least a portion of the instructional animation, detecting an occurrence of a condition that corresponds to initiation of the biometric enrollment process; and in response to detecting the occurrence of the condition that corresponds to initiation of the biometric enrollment process: displaying a progress indicator that corresponds to the simulated progress indicator; and displaying, at a location that was previously occupied by the representation of the simulation of the biometric feature in the biometric enrollment introduction interface, a representation of the biometric feature of the user as determined by the one or more biometric sensors of the device. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more input devices; one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: displaying, on the display, a first user interface; while displaying the first user interface, detecting an occurrence of a condition that corresponds to introduction of a biometric enrollment process for enrolling a biometric feature; in response to detecting the occurrence of the condition that corresponds to introduction of the biometric enrollment process, displaying a biometric enrollment introduction interface, wherein displaying the biometric enrollment introduction interface includes concurrently displaying: a representation of a simulation of the biometric feature; and a simulated progress indicator; while displaying the biometric enrollment introduction interface, displaying an instructional animation that includes displaying movement of the representation of the simulation of the biometric feature and incremental advancement of the simulated progress indicator; after displaying at least a portion of the instructional animation, detecting an occurrence of a condition that corresponds to initiation of the biometric enrollment process; and in response to detecting the occurrence of the condition that corresponds to initiation of the biometric enrollment process: displaying a progress indicator that corresponds to the simulated progress indicator; and displaying, at a location that was previously occupied by the representation of the simulation of the biometric feature in the biometric enrollment introduction interface, a representation of the biometric feature of the user as determined by the one or more biometric sensors of the device. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more input devices; one or more biometric sensors; a display; means for displaying, on the display, a first user interface; means for while displaying the first user interface, detecting an occurrence of a condition that corresponds to introduction of a biometric enrollment process for enrolling a biometric feature; means for in response to detecting the occurrence of the condition that corresponds to introduction of the biometric enrollment process, displaying a biometric enrollment introduction interface, wherein displaying the biometric enrollment introduction interface includes concurrently displaying: a representation of a simulation of the biometric feature; and a simulated progress indicator; means for while displaying the biometric enrollment introduction interface, displaying an instructional animation that includes displaying movement of the representation of the simulation of the biometric feature and incremental advancement of the simulated progress indicator; means for after displaying at least a portion of the instructional animation, detecting an occurrence of a condition that corresponds to initiation of the biometric enrollment process; and means for in response to detecting the occurrence of the condition that corresponds to initiation of the biometric enrollment process: means for displaying a progress indicator that corresponds to the simulated progress indicator; and means for displaying, at a location that was previously occupied by the representation of the simulation of the biometric feature in the biometric enrollment introduction interface, a representation of the biometric feature of the user as determined by the one or more biometric sensors of the device. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with one or more cameras and a display: displaying, on the display, a first user interface; while displaying the first user interface, detecting an occurrence of a condition that corresponds to initiating a biometric enrollment process for enrolling a respective type of biometric feature; in response to detecting the occurrence of a condition that corresponds to initiating the biometric enrollment process, displaying, on the display, a digital viewfinder including a preview of image data captured by the one or more cameras; and after initiating the biometric enrollment process: in accordance with a determination that a biometric feature of the respective type that meets alignment criteria has been detected in afield of view of the one or more cameras, emphasizing a first portion of the field of view of the one or more cameras relative to a second portion of the field of view of the one or more cameras; and in accordance with a determination that the biometric feature of the respective type that meets alignment criteria has not been detected in the field of view of the one or more cameras, maintaining display of the digital viewfinder without emphasizing the first portion of the field of view of the one or more cameras relative to the second portion of the field of view of the one or more cameras. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more cameras and a display, the one or more programs including instructions for: displaying, on the display, a first user interface; while displaying the first user interface, detecting an occurrence of a condition that corresponds to initiating a biometric enrollment process for enrolling a respective type of biometric feature; in response to detecting the occurrence of a condition that corresponds to initiating the biometric enrollment process, displaying, on the display, a digital viewfinder including a preview of image data captured by the one or more cameras; and after initiating the biometric enrollment process: in accordance with a determination that a biometric feature of the respective type that meets alignment criteria has been detected in afield of view of the one or more cameras, emphasizing a first portion of the field of view of the one or more cameras relative to a second portion of the field of view of the one or more cameras; and in accordance with a determination that the biometric feature of the respective type that meets alignment criteria has not been detected in the field of view of the one or more cameras, maintaining display of the digital viewfinder without emphasizing the first portion of the field of view of the one or more cameras relative to the second portion of the field of view of the one or more cameras. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more cameras and a display, the one or more programs including instructions for: displaying, on the display, a first user interface; while displaying the first user interface, detecting an occurrence of a condition that corresponds to initiating a biometric enrollment process for enrolling a respective type of biometric feature; in response to detecting the occurrence of a condition that corresponds to initiating the biometric enrollment process, displaying, on the display, a digital viewfinder including a preview of image data captured by the one or more cameras; and after initiating the biometric enrollment process: in accordance with a determination that a biometric feature of the respective type that meets alignment criteria has been detected in afield of view of the one or more cameras, emphasizing a first portion of the field of view of the one or more cameras relative to a second portion of the field of view of the one or more cameras; and in accordance with a determination that the biometric feature of the respective type that meets alignment criteria has not been detected in the field of view of the one or more cameras, maintaining display of the digital viewfinder without emphasizing the first portion of the field of view of the one or more cameras relative to the second portion of the field of view of the one or more cameras. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more cameras; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: displaying, on the display, a first user interface; while displaying the first user interface, detecting an occurrence of a condition that corresponds to initiating a biometric enrollment process for enrolling a respective type of biometric feature; in response to detecting the occurrence of a condition that corresponds to initiating the biometric enrollment process, displaying, on the display, a digital viewfinder including a preview of image data captured by the one or more cameras; and after initiating the biometric enrollment process: in accordance with a determination that a biometric feature of the respective type that meets alignment criteria has been detected in afield of view of the one or more cameras, emphasizing a first portion of the field of view of the one or more cameras relative to a second portion of the field of view of the one or more cameras; and in accordance with a determination that the biometric feature of the respective type that meets alignment criteria has not been detected in the field of view of the one or more cameras, maintaining display of the digital viewfinder without emphasizing the first portion of the field of view of the one or more cameras relative to the second portion of the field of view of the one or more cameras. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more cameras; a display; one or more processors; means for displaying, on the display, a first user interface; means for while displaying the first user interface, detecting an occurrence of a condition that corresponds to initiating a biometric enrollment process for enrolling a respective type of biometric feature; means for in response to detecting the occurrence of a condition that corresponds to initiating the biometric enrollment process, displaying, on the display, a digital viewfinder including a preview of image data captured by the one or more cameras; and after initiating the biometric enrollment process: means for in accordance with a determination that a biometric feature of the respective type that meets alignment criteria has been detected in afield of view of the one or more cameras, emphasizing a first portion of the field of view of the one or more cameras relative to a second portion of the field of view of the one or more cameras; and means for in accordance with a determination that a biometric feature of the respective type that meets alignment criteria has not been detected in the field of view of the one or more cameras, maintaining display of the digital viewfinder without emphasizing the first portion of the field of view of the one or more cameras relative to the second portion of the field of view of the one or more cameras. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with one or more biometric sensors and a display: concurrently displaying, on the display a biometric enrollment interface, wherein displaying the biometric enrollment interface includes concurrently displaying: a representation of a biometric feature, wherein the representation of the biometric feature has an orientation determined based on an alignment of the biometric feature to one or more biometric sensors of the device; and a progress indicator including a first progress-indicator portion at a first position on the display relative to the representation of the biometric feature and a second progress-indicator portion at a second position on the display relative to the representation of the biometric feature, wherein the representation of the biometric feature is displayed between the first position and the second position on the display; while concurrently displaying the representation of the biometric feature and the progress indicator, detecting a change in the orientation of the biometric feature relative to the one or more biometric sensors; and in response to detecting the change in the orientation of the biometric feature relative to the one or more biometric sensors: in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion, updating one or more visual characteristics of the first progress-indicator portion; and in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a second portion of the biometric feature that corresponds to the second progress-indicator portion, updating one or more visual characteristics of the second progress-indicator portion. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: concurrently displaying, on the display a biometric enrollment interface, wherein displaying the biometric enrollment interface includes concurrently displaying: a representation of a biometric feature, wherein the representation of the biometric feature has an orientation determined based on an alignment of the biometric feature to one or more biometric sensors of the device; and a progress indicator including a first progress-indicator portion at a first position on the display relative to the representation of the biometric feature and a second progress-indicator portion at a second position on the display relative to the representation of the biometric feature, wherein the representation of the biometric feature is displayed between the first position and the second position on the display; while concurrently displaying the representation of the biometric feature and the progress indicator, detecting a change in the orientation of the biometric feature relative to the one or more biometric sensors; and in response to detecting the change in the orientation of the biometric feature relative to the one or more biometric sensors: in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion, updating one or more visual characteristics of the first progress-indicator portion; and in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a second portion of the biometric feature that corresponds to the second progress-indicator portion, updating one or more visual characteristics of the second progress-indicator portion. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: concurrently displaying, on the display a biometric enrollment interface, wherein displaying the biometric enrollment interface includes concurrently displaying: a representation of a biometric feature, wherein the representation of the biometric feature has an orientation determined based on an alignment of the biometric feature to one or more biometric sensors of the device; and a progress indicator including a first progress-indicator portion at a first position on the display relative to the representation of the biometric feature and a second progress-indicator portion at a second position on the display relative to the representation of the biometric feature, wherein the representation of the biometric feature is displayed between the first position and the second position on the display; while concurrently displaying the representation of the biometric feature and the progress indicator, detecting a change in the orientation of the biometric feature relative to the one or more biometric sensors; and in response to detecting the change in the orientation of the biometric feature relative to the one or more biometric sensors: in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion, updating one or more visual characteristics of the first progress-indicator portion; and in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a second portion of the biometric feature that corresponds to the second progress-indicator portion, updating one or more visual characteristics of the second progress-indicator portion. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for concurrently displaying, on the display a biometric enrollment interface, wherein displaying the biometric enrollment interface includes concurrently displaying: a representation of a biometric feature, wherein the representation of the biometric feature has an orientation determined based on an alignment of the biometric feature to one or more biometric sensors of the device; and a progress indicator including a first progress-indicator portion at a first position on the display relative to the representation of the biometric feature and a second progress-indicator portion at a second position on the display relative to the representation of the biometric feature, wherein the representation of the biometric feature is displayed between the first position and the second position on the display; while concurrently displaying the representation of the biometric feature and the progress indicator, detecting a change in the orientation of the biometric feature relative to the one or more biometric sensors; and in response to detecting the change in the orientation of the biometric feature relative to the one or more biometric sensors: in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion, updating one or more visual characteristics of the first progress-indicator portion; and in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a second portion of the biometric feature that corresponds to the second progress-indicator portion, updating one or more visual characteristics of the second progress-indicator portion. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; means for concurrently displaying, on the display a biometric enrollment interface, wherein displaying the biometric enrollment interface includes concurrently displaying: a representation of a biometric feature, wherein the representation of the biometric feature has an orientation determined based on an alignment of the biometric feature to one or more biometric sensors of the device; and a progress indicator including a first progress-indicator portion at a first position on the display relative to the representation of the biometric feature and a second progress-indicator portion at a second position on the display relative to the representation of the biometric feature, wherein the representation of the biometric feature is displayed between the first position and the second position on the display; means for while concurrently displaying the representation of the biometric feature and the progress indicator, detecting a change in the orientation of the biometric feature relative to the one or more biometric sensors; and means for in response to detecting the change in the orientation of the biometric feature relative to the one or more biometric sensors: means for in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion, updating one or more visual characteristics of the first progress-indicator portion; and means for in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a second portion of the biometric feature that corresponds to the second progress-indicator portion, updating one or more visual characteristics of the second progress-indicator portion. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with one or more biometric sensors and a display: displaying, on the display, a biometric enrollment user interface for enrolling a biometric feature, wherein displaying the biometric enrollment user interface includes displaying a representation of the biometric feature, wherein the appearance of the representation of the biometric feature changes as the orientation of the biometric feature relative to the one or more biometric sensors changes; while displaying the biometric enrollment user interface, detecting that enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature; and in response to detecting that the enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature, outputting a respective prompt to move the biometric feature in a respective manner, wherein the respective prompt is selected based on an enrollment state of one or more portions of the biometric feature, including: in accordance with a determination that the enrollment-prompt criteria have been met with respect to a first portion of the biometric feature that can be enrolled by moving the biometric feature in a first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the first manner; and in accordance with a determination that the enrollment-prompt criteria have been met with respect to a second portion of the biometric feature that can be enrolled by moving the biometric feature in a second manner, different from the first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the second manner. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: displaying, on the display, a biometric enrollment user interface for enrolling a biometric feature, wherein displaying the biometric enrollment user interface includes displaying a representation of the biometric feature, wherein the appearance of the representation of the biometric feature changes as the orientation of the biometric feature relative to the one or more biometric sensors changes; while displaying the biometric enrollment user interface, detecting that enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature; and in response to detecting that the enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature, outputting a respective prompt to move the biometric feature in a respective manner, wherein the respective prompt is selected based on an enrollment state of one or more portions of the biometric feature, including: in accordance with a determination that the enrollment-prompt criteria have been met with respect to a first portion of the biometric feature that can be enrolled by moving the biometric feature in a first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the first manner; and in accordance with a determination that the enrollment-prompt criteria have been met with respect to a second portion of the biometric feature that can be enrolled by moving the biometric feature in a second manner, different from the first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the second manner. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: displaying, on the display, a biometric enrollment user interface for enrolling a biometric feature, wherein displaying the biometric enrollment user interface includes displaying a representation of the biometric feature, wherein the appearance of the representation of the biometric feature changes as the orientation of the biometric feature relative to the one or more biometric sensors changes; while displaying the biometric enrollment user interface, detecting that enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature; and in response to detecting that the enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature, outputting a respective prompt to move the biometric feature in a respective manner, wherein the respective prompt is selected based on an enrollment state of one or more portions of the biometric feature, including: in accordance with a determination that the enrollment-prompt criteria have been met with respect to a first portion of the biometric feature that can be enrolled by moving the biometric feature in a first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the first manner; and in accordance with a determination that the enrollment-prompt criteria have been met with respect to a second portion of the biometric feature that can be enrolled by moving the biometric feature in a second manner, different from the first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the second manner. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for displaying, on the display, a biometric enrollment user interface for enrolling a biometric feature, wherein displaying the biometric enrollment user interface includes displaying a representation of the biometric feature, wherein the appearance of the representation of the biometric feature changes as the orientation of the biometric feature relative to the one or more biometric sensors changes; while displaying the biometric enrollment user interface, detecting that enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature; and in response to detecting that the enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature, outputting a respective prompt to move the biometric feature in a respective manner, wherein the respective prompt is selected based on an enrollment state of one or more portions of the biometric feature, including: in accordance with a determination that the enrollment-prompt criteria have been met with respect to a first portion of the biometric feature that can be enrolled by moving the biometric feature in a first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the first manner; and in accordance with a determination that the enrollment-prompt criteria have been met with respect to a second portion of the biometric feature that can be enrolled by moving the biometric feature in a second manner, different from the first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the second manner. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; means for displaying, on the display, a biometric enrollment user interface for enrolling a biometric feature, wherein displaying the biometric enrollment user interface includes displaying a representation of the biometric feature, wherein the appearance of the representation of the biometric feature changes as the orientation of the biometric feature relative to the one or more biometric sensors changes; means for while displaying the biometric enrollment user interface, detecting that enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature; and means for in response to detecting that the enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature, outputting a respective prompt to move the biometric feature in a respective manner, wherein the respective prompt is selected based on an enrollment state of one or more portions of the biometric feature, including: means for in accordance with a determination that the enrollment-prompt criteria have been met with respect to a first portion of the biometric feature that can be enrolled by moving the biometric feature in a first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the first manner; and means for in accordance with a determination that the enrollment-prompt criteria have been met with respect to a second portion of the biometric feature that can be enrolled by moving the biometric feature in a second manner, different from the first manner, outputting the respective prompt includes outputting a prompt to move the biometric feature in the second manner. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with one or more biometric sensors and a display: concurrently displaying, on the display: an application interface corresponding to an application; and a biometric authentication interface controlled by an operating system of the electronic device, wherein the biometric authentication interface is displayed over a portion of the application interface; while displaying the biometric authentication interface, obtaining, from the one or more biometric sensors, biometric data corresponding to at least a portion of a biometric feature; and in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria: providing authentication information to the application indicating the biometric authentication criteria have been satisfied with respect to the one or more portions of the biometric feature; and after providing authentication information to the application, maintaining display of the biometric authentication interface for a predetermined amount of time. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: concurrently displaying, on the display: an application interface corresponding to an application; and a biometric authentication interface controlled by an operating system of the electronic device, wherein the biometric authentication interface is displayed over a portion of the application interface; while displaying the biometric authentication interface, obtaining, from the one or more biometric sensors, biometric data corresponding to at least a portion of a biometric feature; and in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria: providing authentication information to the application indicating the biometric authentication criteria have been satisfied with respect to the one or more portions of the biometric feature; and after providing authentication information to the application, maintaining display of the biometric authentication interface for a predetermined amount of time. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: concurrently displaying, on the display: an application interface corresponding to an application; and a biometric authentication interface controlled by an operating system of the electronic device, wherein the biometric authentication interface is displayed over a portion of the application interface; while displaying the biometric authentication interface, obtaining, from the one or more biometric sensors, biometric data corresponding to at least a portion of a biometric feature; and in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria: providing authentication information to the application indicating the biometric authentication criteria have been satisfied with respect to the one or more portions of the biometric feature; and after providing authentication information to the application, maintaining display of the biometric authentication interface for a predetermined amount of time. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for concurrently displaying, on the display: an application interface corresponding to an application; and a biometric authentication interface controlled by an operating system of the electronic device, wherein the biometric authentication interface is displayed over a portion of the application interface; while displaying the biometric authentication interface, obtaining, from the one or more biometric sensors, biometric data corresponding to at least a portion of a biometric feature; and in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria: providing authentication information to the application indicating the biometric authentication criteria have been satisfied with respect to the one or more portions of the biometric feature; and after providing authentication information to the application, maintaining display of the biometric authentication interface for a predetermined amount of time. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; means for concurrently displaying, on the display: an application interface corresponding to an application; and a biometric authentication interface controlled by an operating system of the electronic device, wherein the biometric authentication interface is displayed over a portion of the application interface; means for while displaying the biometric authentication interface, obtaining, from the one or more biometric sensors, biometric data corresponding to at least a portion of a biometric feature; and means for in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria: means for providing authentication information to the application indicating the biometric authentication criteria have been satisfied with respect to the one or more portions of the biometric feature; and means for after providing authentication information to the application, maintaining display of the biometric authentication interface for a predetermined amount of time. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with one or more biometric sensors and a display: displaying, on the display, an application interface including a fillable field; while displaying the application interface, receiving a request to autofill the fillable field of the application interface; and in response to receiving the request to autofill the fillable field of the application interface: in accordance with a determination that the fillable field of the application interface is associated with data of a first type, autofilling the fillable field with data of the first type; and in accordance with a determination that the fillable field of the application is associated with data of a second type and that at least a portion of a biometric feature, determined based on the data obtained from the one or more biometric sensors that corresponds to the biometric feature, satisfies biometric authentication criteria, autofilling the fillable field with data of the second type. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs for execution by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs comprising instructions for: displaying, on the display, an application interface including a fillable field; while displaying the application interface, receiving a request to autofill the fillable field of the application interface; and in response to receiving the request to autofill the fillable field of the application interface: in accordance with a determination that the fillable field of the application interface is associated with data of a first type, autofilling the fillable field with data of the first type; and in accordance with a determination that the fillable field of the application is associated with data of a second type and that at least a portion of a biometric feature, determined based on the data obtained from the one or more biometric sensors that corresponds to the biometric feature, satisfies biometric authentication criteria, autofilling the fillable field with data of the second type. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs for execution by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs comprising instructions for: displaying, on the display, an application interface including a fillable field; while displaying the application interface, receiving a request to autofill the fillable field of the application interface; and in response to receiving the request to autofill the fillable field of the application interface: in accordance with a determination that the fillable field of the application interface is associated with data of a first type, autofilling the fillable field with data of the first type; and in accordance with a determination that the fillable field of the application is associated with data of a second type and that at least a portion of a biometric feature, determined based on the data obtained from the one or more biometric sensors that corresponds to the biometric feature, satisfies biometric authentication criteria, autofilling the fillable field with data of the second type. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for displaying, on the display, an application interface including a fillable field; while displaying the application interface, receiving a request to autofill the fillable field of the application interface; and in response to receiving the request to autofill the fillable field of the application interface: in accordance with a determination that the fillable field of the application interface is associated with data of a first type, autofilling the fillable field with data of the first type; and in accordance with a determination that the fillable field of the application is associated with data of a second type and that at least a portion of a biometric feature, determined based on the data obtained from the one or more biometric sensors that corresponds to the biometric feature, satisfies biometric authentication criteria, autofilling the fillable field with data of the second type. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; means for displaying, on the display, an application interface including a fillable field; means for while displaying the application interface, receiving a request to autofill the fillable field of the application interface; and means for in response to receiving the request to autofill the fillable field of the application interface: means for in accordance with a determination that the fillable field of the application interface is associated with data of a first type, autofilling the fillable field with data of the first type; and means for in accordance with a determination that the fillable field of the application is associated with data of a second type and that at least a portion of a biometric feature, determined based on the data obtained from the one or more biometric sensors that corresponds to the biometric feature, satisfies biometric authentication criteria, autofilling the fillable field with data of the second type. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device having one or more biometric sensors and a display: detecting that device wake criteria have been met; in response to detecting that the device wake criteria have been met transitioning the electronic device from a first visual state to a second visual state; and after transitioning the device to the second visual state: in accordance with a determination that biometric authentication criteria has been met based on biometric data provided by the one or more biometric sensors, transitioning the electronic device from the second visual state to a third visual state, wherein the transition from the second visual state to the third visual state is a continuation of the transition from the first visual state to the second visual state; and in accordance with a determination that biometric authentication criteria has been not met based on biometric data provided by the one or more biometric sensors, maintaining the electronic device in the second visual state. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: detecting that device wake criteria have been met; in response to detecting that the device wake criteria have been met transitioning the electronic device from a first visual state to a second visual state; and after transitioning the device to the second visual state: in accordance with a determination that biometric authentication criteria has been met based on biometric data provided by the one or more biometric sensors, transitioning the electronic device from the second visual state to a third visual state, wherein the transition from the second visual state to the third visual state is a continuation of the transition from the first visual state to the second visual state; and in accordance with a determination that biometric authentication criteria has been not met based on biometric data provided by the one or more biometric sensors, maintaining the electronic device in the second visual state. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: detecting that device wake criteria have been met; in response to detecting that the device wake criteria have been met transitioning the electronic device from a first visual state to a second visual state; and after transitioning the device to the second visual state: in accordance with a determination that biometric authentication criteria has been met based on biometric data provided by the one or more biometric sensors, transitioning the electronic device from the second visual state to a third visual state, wherein the transition from the second visual state to the third visual state is a continuation of the transition from the first visual state to the second visual state; and in accordance with a determination that biometric authentication criteria has been not met based on biometric data provided by the one or more biometric sensors, maintaining the electronic device in the second visual state. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for detecting that device wake criteria have been met; in response to detecting that the device wake criteria have been met transitioning the electronic device from a first visual state to a second visual state; and after transitioning the device to the second visual state: in accordance with a determination that biometric authentication criteria has been met based on biometric data provided by the one or more biometric sensors, transitioning the electronic device from the second visual state to a third visual state, wherein the transition from the second visual state to the third visual state is a continuation of the transition from the first visual state to the second visual state; and in accordance with a determination that biometric authentication criteria has been not met based on biometric data provided by the one or more biometric sensors, maintaining the electronic device in the second visual state. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; means for detecting that device wake criteria have been met; means for in response to detecting that the device wake criteria have been met transitioning the electronic device from a first visual state to a second visual state; and means for after transitioning the device to the second visual state: means for in accordance with a determination that biometric authentication criteria has been met based on biometric data provided by the one or more biometric sensors, transitioning the electronic device from the second visual state to a third visual state, wherein the transition from the second visual state to the third visual state is a continuation of the transition from the first visual state to the second visual state; and means for in accordance with a determination that biometric authentication criteria has been not met based on biometric data provided by the one or more biometric sensors, maintaining the electronic device in the second visual state. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device having one or more biometric sensors and a display: while the electronic device is in a locked state, detecting a condition that is associated with performing a biometric authentication check using a biometric sensor without an explicit input from the user requesting biometric authentication; and in response to detecting the condition, performing a first biometric authentication check, including: capturing first biometric data using the one or more biometric sensors; after capturing the first biometric data: in accordance with a determination that the first biometric data satisfies biometric authentication criteria, transitioning the device from the locked state to an unlocked state; and in accordance with a determination that the first biometric data does not satisfy the biometric authentication criteria, maintaining the device in the locked state; after the performing the first biometric authentication check, detecting, via the device, a request to perform a respective operation without receiving further authentication information from the user; and in response to detecting the request to perform the respective operation: in accordance with a determination that the respective operation does not require authentication, performing the respective operation; in accordance with a determination that the respective operation requires authentication and that the device is in the unlocked state, performing the respective operation; and in accordance with a determination that the respective operation requires authentication and that the device is in the locked state: capturing second biometric data using the one or more biometric sensors without an explicit input from the user requesting a second biometric authentication check; and after capturing the second biometric data, performing the second biometric authentication check, including: in accordance with a determination that the second biometric data satisfies the biometric authentication criteria, performing the respective operation; and in accordance with a determination that the second biometric data does not satisfy the biometric authentication criteria, forgoing performance of the respective operation. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: while the electronic device is in a locked state, detecting a condition that is associated with performing a biometric authentication check using a biometric sensor without an explicit input from the user requesting biometric authentication; and in response to detecting the condition, performing a first biometric authentication check, including: capturing first biometric data using the one or more biometric sensors; after capturing the first biometric data: in accordance with a determination that the first biometric data satisfies biometric authentication criteria, transitioning the device from the locked state to an unlocked state; and in accordance with a determination that the first biometric data does not satisfy the biometric authentication criteria, maintaining the device in the locked state; after the performing the first biometric authentication check, detecting, via the device, a request to perform a respective operation without receiving further authentication information from the user; and in response to detecting the request to perform the respective operation: in accordance with a determination that the respective operation does not require authentication, performing the respective operation; in accordance with a determination that the respective operation requires authentication and that the device is in the unlocked state, performing the respective operation; and in accordance with a determination that the respective operation requires authentication and that the device is in the locked state: capturing second biometric data using the one or more biometric sensors without an explicit input from the user requesting a second biometric authentication check; and after capturing the second biometric data, performing the second biometric authentication check, including: in accordance with a determination that the second biometric data satisfies the biometric authentication criteria, performing the respective operation; and in accordance with a determination that the second biometric data does not satisfy the biometric authentication criteria, forgoing performance of the respective operation. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: while the electronic device is in a locked state, detecting a condition that is associated with performing a biometric authentication check using a biometric sensor without an explicit input from the user requesting biometric authentication; and in response to detecting the condition, performing a first biometric authentication check, including: capturing first biometric data using the one or more biometric sensors; after capturing the first biometric data: in accordance with a determination that the first biometric data satisfies biometric authentication criteria, transitioning the device from the locked state to an unlocked state; and in accordance with a determination that the first biometric data does not satisfy the biometric authentication criteria, maintaining the device in the locked state; after the performing the first biometric authentication check, detecting, via the device, a request to perform a respective operation without receiving further authentication information from the user; and in response to detecting the request to perform the respective operation: in accordance with a determination that the respective operation does not require authentication, performing the respective operation; in accordance with a determination that the respective operation requires authentication and that the device is in the unlocked state, performing the respective operation; and in accordance with a determination that the respective operation requires authentication and that the device is in the locked state: capturing second biometric data using the one or more biometric sensors without an explicit input from the user requesting a second biometric authentication check; and after capturing the second biometric data, performing the second biometric authentication check, including: in accordance with a determination that the second biometric data satisfies the biometric authentication criteria, performing the respective operation; and in accordance with a determination that the second biometric data does not satisfy the biometric authentication criteria, forgoing performance of the respective operation. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for while the electronic device is in a locked state, detecting a condition that is associated with performing a biometric authentication check using a biometric sensor without an explicit input from the user requesting biometric authentication; and in response to detecting the condition, performing a first biometric authentication check, including: capturing first biometric data using the one or more biometric sensors; after capturing the first biometric data: in accordance with a determination that the first biometric data satisfies biometric authentication criteria, transitioning the device from the locked state to an unlocked state; and in accordance with a determination that the first biometric data does not satisfy the biometric authentication criteria, maintaining the device in the locked state; after the performing the first biometric authentication check, detecting, via the device, a request to perform a respective operation without receiving further authentication information from the user; and in response to detecting the request to perform the respective operation: in accordance with a determination that the respective operation does not require authentication, performing the respective operation; in accordance with a determination that the respective operation requires authentication and that the device is in the unlocked state, performing the respective operation; and in accordance with a determination that the respective operation requires authentication and that the device is in the locked state: capturing second biometric data using the one or more biometric sensors without an explicit input from the user requesting a second biometric authentication check; and after capturing the second biometric data, performing the second biometric authentication check, including: in accordance with a determination that the second biometric data satisfies the biometric authentication criteria, performing the respective operation; and in accordance with a determination that the second biometric data does not satisfy the biometric authentication criteria, forgoing performance of the respective operation. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; means for while the electronic device is in a locked state, detecting a condition that is associated with performing a biometric authentication check using a biometric sensor without an explicit input from the user requesting biometric authentication; and means for in response to detecting the condition, performing a first biometric authentication check, including: means for capturing first biometric data using the one or more biometric sensors; means for after capturing the first biometric data: means for in accordance with a determination that the first biometric data satisfies biometric authentication criteria, transitioning the device from the locked state to an unlocked state; and means for in accordance with a determination that the first biometric data does not satisfy the biometric authentication criteria, maintaining the device in the locked state; means for after the performing the first biometric authentication check, detecting, via the device, a request to perform a respective operation without receiving further authentication information from the user; and means for in response to detecting the request to perform the respective operation: means for in accordance with a determination that the respective operation does not require authentication, performing the respective operation; means for in accordance with a determination that the respective operation requires authentication and that the device is in the unlocked state, performing the respective operation; and means for in accordance with a determination that the respective operation requires authentication and that the device is in the locked state: means for capturing second biometric data using the one or more biometric sensors without an explicit input from the user requesting a second biometric authentication check; and means for after capturing the second biometric data, performing the second biometric authentication check, including: means for in accordance with a determination that the second biometric data satisfies the biometric authentication criteria, performing the respective operation; and means for in accordance with a determination that the second biometric data does not satisfy the biometric authentication criteria, forgoing performance of the respective operation. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with a display, a button, and one or more biometric sensors separate from the button: while the electronic device is in a first state in which a respective function of the device is disabled, detecting one or more activations of the button; and in response to detecting the one or more activations of the button: capturing, with the one or more biometric sensors that are separate from the button, biometric data; in accordance with a determination that the biometric data satisfies biometric authentication criteria, transitioning the electronic device to a second state in which the respective function of the device is enabled; and in accordance with a determination that the biometric data does not satisfy the biometric authentication criteria, maintaining the electronic device in the first state and displaying, on the display, an indication that biometric authentication has failed. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display, a button, and one or more biometric sensors separate from the button, the one or more programs including instructions for: while the electronic device is in a first state in which a respective function of the device is disabled, detecting one or more activations of the button; and in response to detecting the one or more activations of the button: capturing, with the one or more biometric sensors that are separate from the button, biometric data; in accordance with a determination that the biometric data satisfies biometric authentication criteria, transitioning the electronic device to a second state in which the respective function of the device is enabled; and in accordance with a determination that the biometric data does not satisfy the biometric authentication criteria, maintaining the electronic device in the first state and displaying, on the display, an indication that biometric authentication has failed. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display, a button, and one or more biometric sensors separate from the button, the one or more programs including instructions for: while the electronic device is in a first state in which a respective function of the device is disabled, detecting one or more activations of the button; and in response to detecting the one or more activations of the button: capturing, with the one or more biometric sensors that are separate from the button, biometric data; in accordance with a determination that the biometric data satisfies biometric authentication criteria, transitioning the electronic device to a second state in which the respective function of the device is enabled; and in accordance with a determination that the biometric data does not satisfy the biometric authentication criteria, maintaining the electronic device in the first state and displaying, on the display, an indication that biometric authentication has failed. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: a display; a button; one or more biometric sensors separate from the button; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: while the electronic device is in a first state in which a respective function of the device is disabled, detecting one or more activations of the button; and in response to detecting the one or more activations of the button: capturing, with the one or more biometric sensors that are separate from the button, biometric data; in accordance with a determination that the biometric data satisfies biometric authentication criteria, transitioning the electronic device to a second state in which the respective function of the device is enabled; and in accordance with a determination that the biometric data does not satisfy the biometric authentication criteria, maintaining the electronic device in the first state and displaying, on the display, an indication that biometric authentication has failed. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: a display; a button; one or more biometric sensors separate from the button; means for while the electronic device is in a first state in which a respective function of the device is disabled, detecting one or more activations of the button; and means for in response to detecting the one or more activations of the button: means for capturing, with the one or more biometric sensors that are separate from the button, biometric data; means for in accordance with a determination that the biometric data satisfies biometric authentication criteria, transitioning the electronic device to a second state in which the respective function of the device is enabled; and means for in accordance with a determination that the biometric data does not satisfy the biometric authentication criteria, maintaining the electronic device in the first state and displaying, on the display, an indication that biometric authentication has failed. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device having one or more biometric sensors and a display: detecting a request to perform a respective operation that requires authentication; and in response to detecting the request to perform the respective operation that requires authentication: in accordance with a determination that the device is unlocked, performing the respective operation; and in accordance with a determination that the device is locked and a first form of authentication is available for use, wherein the first form of authentication is a form of biometric authentication based on data obtained by the one or more biometric sensors, displaying, on the display, an authentication indicator for the first form of authentication without displaying one or more affordances for using a second form of authentication. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: detecting a request to perform a respective operation that requires authentication; and in response to detecting the request to perform the respective operation that requires authentication: in accordance with a determination that the device is unlocked, performing the respective operation; and in accordance with a determination that the device is locked and a first form of authentication is available for use, wherein the first form of authentication is a form of biometric authentication based on data obtained by the one or more biometric sensors, displaying, on the display, an authentication indicator for the first form of authentication without displaying one or more affordances for using a second form of authentication. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors and a display, the one or more programs including instructions for: detecting a request to perform a respective operation that requires authentication; and in response to detecting the request to perform the respective operation that requires authentication: in accordance with a determination that the device is unlocked, performing the respective operation; and in accordance with a determination that the device is locked and a first form of authentication is available for use, wherein the first form of authentication is a form of biometric authentication based on data obtained by the one or more biometric sensors, displaying, on the display, an authentication indicator for the first form of authentication without displaying one or more affordances for using a second form of authentication. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for detecting a request to perform a respective operation that requires authentication; and in response to detecting the request to perform the respective operation that requires authentication: in accordance with a determination that the device is unlocked, performing the respective operation; and in accordance with a determination that the device is locked and a first form of authentication is available for use, wherein the first form of authentication is a form of biometric authentication based on data obtained by the one or more biometric sensors, displaying, on the display, an authentication indicator for the first form of authentication without displaying one or more affordances for using a second form of authentication. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; means for detecting a request to perform a respective operation that requires authentication; and means for in response to detecting the request to perform the respective operation that requires authentication: means for in accordance with a determination that the device is unlocked, performing the respective operation; and means for in accordance with a determination that the device is locked and a first form of authentication is available for use, wherein the first form of authentication is a form of biometric authentication based on data obtained by the one or more biometric sensors, displaying, on the display, an authentication indicator for the first form of authentication without displaying one or more affordances for using a second form of authentication. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with one or more biometric sensors: receiving a first request to perform a respective operation that requires authentication; in response to receiving the first request to perform the respective operation: using the one or more biometric sensors to determine whether biometric authentication criteria are met, wherein the biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the respective operation is detected by the biometric sensors; in accordance with a determination that the biometric authentication criteria are met, performing the respective operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the respective operation; subsequent to the determination that the biometric authentication criteria were not met in response to receiving the first request, receiving a second request to perform the respective operation; and in response to receiving the second request to perform the respective operation: in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors not detecting the presence of a biometric feature of the respective type, using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request; and in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors detecting a biometric feature of the respective type that does not correspond to the authorized biometric feature, forgoing using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors, the one or more programs including instructions for: receiving a first request to perform a respective operation that requires authentication; in response to receiving the first request to perform the respective operation: using the one or more biometric sensors to determine whether biometric authentication criteria are met, wherein the biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the respective operation is detected by the biometric sensors; in accordance with a determination that the biometric authentication criteria are met, performing the respective operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the respective operation; subsequent to the determination that the biometric authentication criteria were not met in response to receiving the first request, receiving a second request to perform the respective operation; and in response to receiving the second request to perform the respective operation: in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors not detecting the presence of a biometric feature of the respective type, using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request; and in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors detecting a biometric feature of the respective type that does not correspond to the authorized biometric feature, forgoing using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors, the one or more programs including instructions for: receiving a first request to perform a respective operation that requires authentication; in response to receiving the first request to perform the respective operation: using the one or more biometric sensors to determine whether biometric authentication criteria are met, wherein the biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the respective operation is detected by the biometric sensors; in accordance with a determination that the biometric authentication criteria are met, performing the respective operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the respective operation; subsequent to the determination that the biometric authentication criteria were not met in response to receiving the first request, receiving a second request to perform the respective operation; and in response to receiving the second request to perform the respective operation: in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors not detecting the presence of a biometric feature of the respective type, using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request; and in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors detecting a biometric feature of the respective type that does not correspond to the authorized biometric feature, forgoing using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: receiving a first request to perform a respective operation that requires authentication; in response to receiving the first request to perform the respective operation: using the one or more biometric sensors to determine whether biometric authentication criteria are met, wherein the biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the respective operation is detected by the biometric sensors; in accordance with a determination that the biometric authentication criteria are met, performing the respective operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the respective operation; subsequent to the determination that the biometric authentication criteria were not met in response to receiving the first request, receiving a second request to perform the respective operation; and in response to receiving the second request to perform the respective operation: in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors not detecting the presence of a biometric feature of the respective type, using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request; and in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors detecting a biometric feature of the respective type that does not correspond to the authorized biometric feature, forgoing using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; means for receiving a first request to perform a respective operation that requires authentication; means, responsive to receiving the first request to perform the respective operation, for: using the one or more biometric sensors to determine whether biometric authentication criteria are met, wherein the biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the respective operation is detected by the biometric sensors; in accordance with a determination that the biometric authentication criteria are met, performing the respective operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the respective operation; means, subsequent to the determination that the biometric authentication criteria were not met in response to receiving the first request, for receiving a second request to perform the respective operation; and means, responsive to receiving the second request to perform the respective operation, for: in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors not detecting the presence of a biometric feature of the respective type, using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request; and in accordance with a determination that the biometric authentication criteria were not met in response to the first request due to the one or more biometric sensors detecting a biometric feature of the respective type that does not correspond to the authorized biometric feature, forgoing using the one or more biometric sensors to determine whether the biometric authentication criteria are met in response to the second request. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with one or more biometric sensors: receiving a first request to perform a first operation that requires authentication; in response to receiving the first request to perform the first operation: using the one or more biometric sensors to determine whether first biometric authentication criteria are met, wherein the first biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the first operation is detected by the biometric sensors; in accordance with a determination that the first biometric authentication criteria are met, performing the first operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the first operation; after performing the first operation, receiving a second request to perform a second operation that requires authentication; and in response to receiving the second request: in accordance with a determination that re-authentication criteria have been met, using the one or more biometric sensors to determine whether second biometric authentication criteria are met, wherein the second biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the second operation is detected by the biometric sensors; and in accordance with a determination that the re-authentication criteria have not been met, performing the second operation without performing biometric authentication and forgoing using the one or more biometric sensors to determine whether the second biometric authentication criteria are met. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors, the one or more programs including instructions for: receiving a first request to perform a first operation that requires authentication; in response to receiving the first request to perform the first operation: using the one or more biometric sensors to determine whether first biometric authentication criteria are met, wherein the first biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the first operation is detected by the biometric sensors; in accordance with a determination that the first biometric authentication criteria are met, performing the first operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the first operation; after performing the first operation, receiving a second request to perform a second operation that requires authentication; and in response to receiving the second request: in accordance with a determination that re-authentication criteria have been met, using the one or more biometric sensors to determine whether second biometric authentication criteria are met, wherein the second biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the second operation is detected by the biometric sensors; and in accordance with a determination that the re-authentication criteria have not been met, performing the second operation without performing biometric authentication and forgoing using the one or more biometric sensors to determine whether the second biometric authentication criteria are met. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with one or more biometric sensors, the one or more programs including instructions for: receiving a first request to perform a first operation that requires authentication; in response to receiving the first request to perform the first operation: using the one or more biometric sensors to determine whether first biometric authentication criteria are met, wherein the first biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the first operation is detected by the biometric sensors; in accordance with a determination that the first biometric authentication criteria are met, performing the first operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the first operation; after performing the first operation, receiving a second request to perform a second operation that requires authentication; and in response to receiving the second request: in accordance with a determination that re-authentication criteria have been met, using the one or more biometric sensors to determine whether second biometric authentication criteria are met, wherein the second biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the second operation is detected by the biometric sensors; and in accordance with a determination that the re-authentication criteria have not been met, performing the second operation without performing biometric authentication and forgoing using the one or more biometric sensors to determine whether the second biometric authentication criteria are met. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: receiving a first request to perform a first operation that requires authentication; in response to receiving the first request to perform the first operation: using the one or more biometric sensors to determine whether first biometric authentication criteria are met, wherein the first biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the first operation is detected by the biometric sensors; in accordance with a determination that the first biometric authentication criteria are met, performing the first operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the first operation; after performing the first operation, receiving a second request to perform a second operation that requires authentication; and in response to receiving the second request: in accordance with a determination that re-authentication criteria have been met, using the one or more biometric sensors to determine whether second biometric authentication criteria are met, wherein the second biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the second operation is detected by the biometric sensors; and in accordance with a determination that the re-authentication criteria have not been met, performing the second operation without performing biometric authentication and forgoing using the one or more biometric sensors to determine whether the second biometric authentication criteria are met. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; means for receiving a first request to perform a first operation that requires authentication; means, responsive to receiving the first request to perform the first operation, for: using the one or more biometric sensors to determine whether first biometric authentication criteria are met, wherein the first biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the first operation is detected by the biometric sensors; in accordance with a determination that the first biometric authentication criteria are met, performing the first operation; and in accordance with a determination that the biometric authentication criteria are not met, forgoing performing the first operation; means, after performing the first operation, receiving a second request to perform a second operation that requires authentication, for; and means, responsive to receiving the second request, for: in accordance with a determination that re-authentication criteria have been met, using the one or more biometric sensors to determine whether second biometric authentication criteria are met, wherein the second biometric authentication criteria include a requirement that a biometric feature of a respective type that is authorized to perform the second operation is detected by the biometric sensors; and in accordance with a determination that the re-authentication criteria have not been met, performing the second operation without performing biometric authentication and forgoing using the one or more biometric sensors to determine whether the second biometric authentication criteria are met. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with a display: receiving a request to display a first portion of respective content; and in response to the request to display the first portion of the respective content: displaying, on the display, at least the first portion of the respective content, the respective content including an element associated with an authentication operation; in accordance with a determination that the element associated with the authentication operation meets visibility criteria, initiating biometric authentication; and in accordance with a determination that the element associated with the authentication operation does not meet the visibility criteria, forgoing initiating biometric authentication. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with a display, the one or more programs including instructions for: receiving a request to display a first portion of respective content; and in response to the request to display the first portion of the respective content: displaying, on the display, at least the first portion of the respective content, the respective content including an element associated with an authentication operation; in accordance with a determination that the element associated with the authentication operation meets visibility criteria, initiating biometric authentication; and in accordance with a determination that the element associated with the authentication operation does not meet the visibility criteria, forgoing initiating biometric authentication. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display, the one or more programs including instructions for: receiving a request to display a first portion of respective content; and in response to the request to display the first portion of the respective content: displaying, on the display, at least the first portion of the respective content, the respective content including an element associated with an authentication operation; in accordance with a determination that the element associated with the authentication operation meets visibility criteria, initiating biometric authentication; and in accordance with a determination that the element associated with the authentication operation does not meet the visibility criteria, forgoing initiating biometric authentication. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: receiving a request to display a first portion of respective content; and in response to the request to display the first portion of the respective content: displaying, on the display, at least the first portion of the respective content, the respective content including an element associated with an authentication operation; in accordance with a determination that the element associated with the authentication operation meets visibility criteria, initiating biometric authentication; and in accordance with a determination that the element associated with the authentication operation does not meet the visibility criteria, forgoing initiating biometric authentication. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: a display; means for receiving a request to display a first portion of respective content; and means, responsive to the request to display the first portion of the respective content, for: displaying, on the display, at least the first portion of the respective content, the respective content including an element associated with an authentication operation; in accordance with a determination that the element associated with the authentication operation meets visibility criteria, initiating biometric authentication; and in accordance with a determination that the element associated with the authentication operation does not meet the visibility criteria, forgoing initiating biometric authentication. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with a display and one or more biometric sensors: detecting a predefined operation corresponding to a credential submission user interface having a credential submission user interface element; and in response to detecting the predefined operation: in accordance with a determination that biometric authentication via the one or more biometric sensors is available, displaying, on the display, the credential submission user interface with a visual indication that presentation of a biometric feature that meets biometric authentication criteria to the one or more biometric sensors will cause credentials to be submitted via the credential submission user interface element. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with a display and one or more biometric sensors, the one or more programs including instructions for: detecting a predefined operation corresponding to a credential submission user interface having a credential submission user interface element; and in response to detecting the predefined operation: in accordance with a determination that biometric authentication via the one or more biometric sensors is available, displaying, on the display, the credential submission user interface with a visual indication that presentation of a biometric feature that meets biometric authentication criteria to the one or more biometric sensors will cause credentials to be submitted via the credential submission user interface element. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with a display and one or more biometric sensors, the one or more programs including instructions for: detecting a predefined operation corresponding to a credential submission user interface having a credential submission user interface element; and in response to detecting the predefined operation: in accordance with a determination that biometric authentication via the one or more biometric sensors is available, displaying, on the display, the credential submission user interface with a visual indication that presentation of a biometric feature that meets biometric authentication criteria to the one or more biometric sensors will cause credentials to be submitted via the credential submission user interface element. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: a display; one or more biometric sensors; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: detecting a predefined operation corresponding to a credential submission user interface having a credential submission user interface element; and in response to detecting the predefined operation: in accordance with a determination that biometric authentication via the one or more biometric sensors is available, displaying, on the display, the credential submission user interface with a visual indication that presentation of a biometric feature that meets biometric authentication criteria to the one or more biometric sensors will cause credentials to be submitted via the credential submission user interface element. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: a display; one or more biometric sensors; means for detecting a predefined operation corresponding to a credential submission user interface having a credential submission user interface element; and means, responsive to detecting the predefined operation, for: in accordance with a determination that biometric authentication via the one or more biometric sensors is available, displaying, on the display, the credential submission user interface with a visual indication that presentation of a biometric feature that meets biometric authentication criteria to the one or more biometric sensors will cause credentials to be submitted via the credential submission user interface element. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with a touch-sensitive display and one or more biometric sensors: displaying, on the touch-sensitive display, a credential entry user interface with a plurality of character entry keys; while displaying the credential entry user interface, receiving, via the touch-sensitive display, a touch gesture input that includes movement of a contact on the touch-sensitive display; and in response to receiving the touch gesture input that includes movement of the contact on the touch-sensitive display: in accordance with a determination that a first set of one or more criteria are met, the first set of one or more criteria including a requirement that biometric authentication is currently enabled on the electronic device, attempting to biometrically authenticate a user of the electronic device based on biometric information captured using the one or more biometric sensors. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a touch-sensitive display and one or more biometric sensors, the one or more programs including instructions for: displaying, on the touch-sensitive display, a credential entry user interface with a plurality of character entry keys; while displaying the credential entry user interface, receiving, via the touch-sensitive display, a touch gesture input that includes movement of a contact on the touch-sensitive display; and in response to receiving the touch gesture input that includes movement of the contact on the touch-sensitive display: in accordance with a determination that a first set of one or more criteria are met, the first set of one or more criteria including a requirement that biometric authentication is currently enabled on the electronic device, attempting to biometrically authenticate a user of the electronic device based on biometric information captured using the one or more biometric sensors. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a touch-sensitive display and one or more biometric sensors, the one or more programs including instructions for: displaying, on the touch-sensitive display, a credential entry user interface with a plurality of character entry keys; while displaying the credential entry user interface, receiving, via the touch-sensitive display, a touch gesture input that includes movement of a contact on the touch-sensitive display; and in response to receiving the touch gesture input that includes movement of the contact on the touch-sensitive display: in accordance with a determination that a first set of one or more criteria are met, the first set of one or more criteria including a requirement that biometric authentication is currently enabled on the electronic device, attempting to biometrically authenticate a user of the electronic device based on biometric information captured using the one or more biometric sensors. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a touch-sensitive display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: displaying, on the touch-sensitive display, a credential entry user interface with a plurality of character entry keys; while displaying the credential entry user interface, receiving, via the touch-sensitive display, a touch gesture input that includes movement of a contact on the touch-sensitive display; and in response to receiving the touch gesture input that includes movement of the contact on the touch-sensitive display: in accordance with a determination that a first set of one or more criteria are met, the first set of one or more criteria including a requirement that biometric authentication is currently enabled on the electronic device, attempting to biometrically authenticate a user of the electronic device based on biometric information captured using the one or more biometric sensors. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a touch-sensitive display; means for displaying, on the touch-sensitive display, a credential entry user interface with a plurality of character entry keys; means for, while displaying the credential entry user interface, receiving, via the touch-sensitive display, a touch gesture input that includes movement of a contact on the touch-sensitive display; and means for, in response to receiving the touch gesture input that includes movement of the contact on the touch-sensitive display: in accordance with a determination that a first set of one or more criteria are met, the first set of one or more criteria including a requirement that biometric authentication is currently enabled on the electronic device, attempting to biometrically authenticate a user of the electronic device based on biometric information captured using the one or more biometric sensors. 
     In accordance with some embodiments, a method is described, the method comprising: at an electronic device with a display and one or more input devices: receiving, via the one or more input devices, a request to perform an operation that requires authentication; and in response to the request to perform the operation that requires authentication: in accordance with a determination that authentication is successful, performing the operation; and in accordance with a determination that authentication is not successful and that a set of error condition criteria is met: displaying, on the display, an indication of an error condition, wherein the indication includes information about the cause of the error condition; and forgoing performing the operation. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display and one or more input devices, the one or more programs including instructions for: receiving, via the one or more input devices, a request to perform an operation that requires authentication; and in response to the request to perform the operation that requires authentication: in accordance with a determination that authentication is successful, performing the operation; and in accordance with a determination that authentication is not successful and that a set of error condition criteria is met: displaying, on the display, an indication of an error condition, wherein the indication includes information about the cause of the error condition; and forgoing performing the operation. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display and one or more input devices, the one or more programs including instructions for: receiving, via the one or more input devices, a request to perform an operation that requires authentication; and in response to the request to perform the operation that requires authentication: in accordance with a determination that authentication is successful, performing the operation; and in accordance with a determination that authentication is not successful and that a set of error condition criteria is met: displaying, on the display, an indication of an error condition, wherein the indication includes information about the cause of the error condition; and forgoing performing the operation. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more input devices; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: receiving, via the one or more input devices, a request to perform an operation that requires authentication; and in response to the request to perform the operation that requires authentication: in accordance with a determination that authentication is successful, performing the operation; and in accordance with a determination that authentication is not successful and that a set of error condition criteria is met: displaying, on the display, an indication of an error condition, wherein the indication includes information about the cause of the error condition; and forgoing performing the operation. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more input devices; a display; means for receiving, via the one or more input devices, a request to perform an operation that requires authentication; and means for, in response to the request to perform the operation that requires authentication: in accordance with a determination that authentication is successful, performing the operation; and in accordance with a determination that authentication is not successful and that a set of error condition criteria is met: displaying, on the display, an indication of an error condition, wherein the indication includes information about the cause of the error condition; and forgoing performing the operation. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with a display and a biometric sensor at a first portion of the electronic device: detecting the existence of an error condition that prevents the biometric sensor from obtaining biometric information about a user of the device; in response to detecting the existence of the error condition, displaying, on the display, an error indication, wherein the error indication is displayed at a location that is proximate to the first portion of the electronic device, including: in accordance with a determination that a user interface of the electronic device is in a first orientation relative to the biometric sensor, displaying the error indication at a first location in the user interface that is proximate to the first portion of the electronic device; and in accordance with a determination that the user interface of the electronic device is in a second orientation relative to the biometric sensor, displaying the error indication at a second location in the user interface that is proximate to the first portion of the electronic device, the first orientation being different from the second orientation. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display and a biometric sensor at a first portion of the electronic device, the one or more programs including instructions for: detecting the existence of an error condition that prevents the biometric sensor from obtaining biometric information about a user of the device; in response to detecting the existence of the error condition, displaying, on the display, an error indication, wherein the error indication is displayed at a location that is proximate to the first portion of the electronic device, including: in accordance with a determination that a user interface of the electronic device is in a first orientation relative to the biometric sensor, displaying the error indication at a first location in the user interface that is proximate to the first portion of the electronic device; and in accordance with a determination that the user interface of the electronic device is in a second orientation relative to the biometric sensor, displaying the error indication at a second location in the user interface that is proximate to the first portion of the electronic device, the first orientation being different from the second orientation. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display and a biometric sensor at a first portion of the electronic device, the one or more programs including instructions for: detecting the existence of an error condition that prevents the biometric sensor from obtaining biometric information about a user of the device; in response to detecting the existence of the error condition, displaying, on the display, an error indication, wherein the error indication is displayed at a location that is proximate to the first portion of the electronic device, including: in accordance with a determination that a user interface of the electronic device is in a first orientation relative to the biometric sensor, displaying the error indication at a first location in the user interface that is proximate to the first portion of the electronic device; and in accordance with a determination that the user interface of the electronic device is in a second orientation relative to the biometric sensor, displaying the error indication at a second location in the user interface that is proximate to the first portion of the electronic device, the first orientation being different from the second orientation. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: a biometric sensor at a first portion of the electronic device; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: detecting the existence of an error condition that prevents the biometric sensor from obtaining biometric information about a user of the device; in response to detecting the existence of the error condition, displaying, on the display, an error indication, wherein the error indication is displayed at a location that is proximate to the first portion of the electronic device, including: in accordance with a determination that a user interface of the electronic device is in a first orientation relative to the biometric sensor, displaying the error indication at a first location in the user interface that is proximate to the first portion of the electronic device; and in accordance with a determination that the user interface of the electronic device is in a second orientation relative to the biometric sensor, displaying the error indication at a second location in the user interface that is proximate to the first portion of the electronic device, the first orientation being different from the second orientation. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: a biometric sensor at a first portion of the electronic device; a display; means for detecting the existence of an error condition that prevents the biometric sensor from obtaining biometric information about a user of the device; means for, in response to detecting the existence of the error condition, displaying, on the display, an error indication, wherein the error indication is displayed at a location that is proximate to the first portion of the electronic device, including: in accordance with a determination that a user interface of the electronic device is in a first orientation relative to the biometric sensor, displaying the error indication at a first location in the user interface that is proximate to the first portion of the electronic device; and in accordance with a determination that the user interface of the electronic device is in a second orientation relative to the biometric sensor, displaying the error indication at a second location in the user interface that is proximate to the first portion of the electronic device, the first orientation being different from the second orientation. 
     In accordance with some examples, a method is described, the method comprising: at an electronic device with a display and one or more biometric sensors: displaying, on the display, a biometric enrollment user interface for initiating biometric enrollment with the one or more biometric sensors; while displaying the biometric enrollment user interface, receiving input corresponding for a request to initiate biometric enrollment; and in response to receiving the input: in accordance with a determination that an orientation of the electronic device satisfies a set of enrollment criteria, initiating a process for enrolling a biometric feature with the one or more biometric sensors; and in accordance with a determination that the orientation of the electronic device does not satisfy the set of enrollment criteria, outputting one or more prompts to change the orientation of the electronic device to a different orientation that satisfies the set of enrollment criteria. 
     In accordance with some examples, a non-transitory computer-readable medium is described, the non-transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display and one or more biometric sensors, the one or more programs including instructions for: displaying, on the display, a biometric enrollment user interface for initiating biometric enrollment with the one or more biometric sensors; while displaying the biometric enrollment user interface, receiving input corresponding for a request to initiate biometric enrollment; and in response to receiving the input: in accordance with a determination that an orientation of the electronic device satisfies a set of enrollment criteria, initiating a process for enrolling a biometric feature with the one or more biometric sensors; and in accordance with a determination that the orientation of the electronic device does not satisfy the set of enrollment criteria, outputting one or more prompts to change the orientation of the electronic device to a different orientation that satisfies the set of enrollment criteria. 
     In accordance with some examples, a transitory computer-readable medium is described, the transitory computer-readable storage medium comprising one or more programs configured to be executed by one or more processors of an electronic device with a display and one or more biometric sensors, the one or more programs including instructions for: displaying, on the display, a biometric enrollment user interface for initiating biometric enrollment with the one or more biometric sensors; while displaying the biometric enrollment user interface, receiving input corresponding for a request to initiate biometric enrollment; and in response to receiving the input: in accordance with a determination that an orientation of the electronic device satisfies a set of enrollment criteria, initiating a process for enrolling a biometric feature with the one or more biometric sensors; and in accordance with a determination that the orientation of the electronic device does not satisfy the set of enrollment criteria, outputting one or more prompts to change the orientation of the electronic device to a different orientation that satisfies the set of enrollment criteria. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: displaying, on the display, a biometric enrollment user interface for initiating biometric enrollment with the one or more biometric sensors; while displaying the biometric enrollment user interface, receiving input corresponding for a request to initiate biometric enrollment; and in response to receiving the input: in accordance with a determination that an orientation of the electronic device satisfies a set of enrollment criteria, initiating a process for enrolling a biometric feature with the one or more biometric sensors; and in accordance with a determination that the orientation of the electronic device does not satisfy the set of enrollment criteria, outputting one or more prompts to change the orientation of the electronic device to a different orientation that satisfies the set of enrollment criteria. 
     In accordance with some examples, an electronic device is described, the electronic device comprising: one or more biometric sensors; a display; means for displaying, on the display, a biometric enrollment user interface for initiating biometric enrollment with the one or more biometric sensors; means for, while displaying the biometric enrollment user interface, receiving input corresponding for a request to initiate biometric enrollment; and means for, in response to receiving the input: in accordance with a determination that an orientation of the electronic device satisfies a set of enrollment criteria, initiating a process for enrolling a biometric feature with the one or more biometric sensors; and in accordance with a determination that the orientation of the electronic device does not satisfy the set of enrollment criteria, outputting one or more prompts to change the orientation of the electronic device to a different orientation that satisfies the set of enrollment criteria. 
     Executable instructions for performing these functions are, optionally, included in a non-transitory computer-readable storage medium or other computer program product configured for execution by one or more processors. Executable instructions for performing these functions are, optionally, included in a transitory computer-readable storage medium or other computer program product configured for execution by one or more processors. 
     Thus, devices are provided with faster, more efficient methods and interfaces for implementing biometric authentication, thereby increasing the effectiveness, efficiency, and user satisfaction with such devices. Such methods and interfaces optionally complement or replace other methods for implementing biometric authentication. 
    
    
     
       DESCRIPTION OF THE FIGURES 
       For a better understanding of the various described examples, reference should be made to the Description of Embodiments below, in conjunction with the following drawings in which like reference numerals refer to corresponding parts throughout the figures. 
         FIG. 1A  is a block diagram illustrating a portable multifunction device with a touch-sensitive display in accordance with some embodiments. 
         FIG. 1B  is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. 
         FIG. 1C  is a block diagram illustrating exemplary components for generating a tactile output, in accordance with some embodiments. 
         FIG. 2  illustrates a portable multifunction device having a touch screen in accordance with some embodiments. 
         FIG. 3  is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface in accordance with some embodiments. 
         FIG. 4A  illustrates an exemplary user interface for a menu of applications on a portable multifunction device in accordance with some embodiments. 
         FIG. 4B  illustrates an exemplary user interface for a multifunction device with a touch-sensitive surface that is separate from the display in accordance with some embodiments. 
         FIGS. 4C-4H  illustrate exemplary tactile output patterns that have a particular waveform, in accordance with some embodiments. 
         FIG. 5A  illustrates a personal electronic device in accordance with some embodiments. 
         FIG. 5B  is a block diagram illustrating a personal electronic device in accordance with some embodiments. 
         FIGS. 5C-5D  illustrate exemplary components of a personal electronic device having a touch-sensitive display and intensity sensors in accordance with some embodiments. 
         FIGS. 5E-5H  illustrate exemplary components and user interfaces of a personal electronic device in accordance with some embodiments. 
         FIG. 6  illustrates exemplary devices connected via one or more communication channels, in accordance with some embodiments. 
         FIGS. 7A-7S  illustrate exemplary user interfaces for a biometric enrollment process tutorial, in accordance with some examples. 
         FIGS. 8A-8C  are a flow diagram illustrating methods of a biometric enrollment process tutorial. 
         FIGS. 9A-9AE  illustrate exemplary user interfaces for aligning a biometric feature for enrollment. 
         FIGS. 10A-10F  are a flow diagram illustrating methods of aligning a biometric feature for enrollment. 
         FIGS. 11A-11O  illustrate exemplary user interfaces for enrolling a biometric feature. 
         FIGS. 12A-12B  are a flow diagram illustrating methods of enrolling a biometric feature. 
         FIGS. 13A-13R  illustrate exemplary user interfaces for providing hints during a biometric enrollment process. 
         FIGS. 14A-14C  are a flow diagram illustrating methods of providing hints during a biometric enrollment process. 
         FIGS. 15A-15T  illustrate exemplary user interfaces for application-based biometric authentication. 
         FIGS. 16A-16E  are a flow diagram illustrating methods of application-based biometric authentication. 
         FIGS. 17A-17AI  illustrate exemplary user interfaces for autofilling biometrically secured fields. 
         FIGS. 18A-18D  are a flow diagram illustrating methods of autofilling biometrically secured fields. 
         FIGS. 19A-19AB  illustrate exemplary user interfaces for unlocking a device using biometric authentication. 
         FIGS. 20A-20F  are a flow diagram illustrating methods of unlocking a device using biometric authentication. 
         FIGS. 21A-21AQ  illustrate exemplary user interfaces for retrying biometric authentication 
         FIGS. 22A-22F  are a flow diagram illustrating methods of for retrying biometric authentication. 
         FIGS. 23A-23Q  illustrate exemplary user interfaces for managing transfers using biometric authentication. 
         FIGS. 24A-24BC  illustrate exemplary user interfaces for managing transfers using biometric authentication. 
         FIGS. 25A-25C  are a flow diagram illustrating methods of managing transfers using biometric authentication. 
         FIGS. 26A-26AS  illustrate exemplary user interfaces for providing interstitial user interfaces during biometric authentication. 
         FIGS. 27A-27E  are a flow diagram illustrating methods of providing interstitial user interfaces during biometric authentication. 
         FIGS. 28A-28AA  illustrate exemplary user interfaces for preventing retrying biometric authentication. 
         FIGS. 29A-29B  are a flow diagram illustrating methods of preventing retrying biometric authentication. 
         FIGS. 30A-30AL  illustrate exemplary user interfaces for cached biometric authentication. 
         FIGS. 31A-31B  are a flow diagram illustrating methods of cached biometric authentication. 
         FIGS. 32A-32W  illustrate exemplary user interfaces for autofilling fillable fields based on visibility criteria. 
         FIG. 33  is a flow diagram illustrating methods of autofilling fillable fields based on visibility criteria. 
         FIGS. 34A-34N  illustrate exemplary user interfaces for automatic log-in using biometric authentication. 
         FIG. 35  is a flow diagram illustrating methods of automatic log-in using biometric authentication. 
         FIGS. 36A-36L  illustrate exemplary user interfaces for retrying biometric authentication at a credential entry user interface, in accordance with some examples. 
         FIGS. 37A-37B  are flow diagrams illustrating a method for retrying biometric authentication at a credential entry user interface using an electronic device, in accordance with some examples. 
         FIGS. 38A-38AD  illustrate exemplary user interfaces for providing indications of error conditions during biometric authentication, in accordance with some examples. 
         FIGS. 39A-39B  are flow diagrams illustrating a method for providing indications of error conditions during biometric authentication, in accordance with some examples 
         FIGS. 40A-40U  illustrate exemplary user interfaces for providing indications about the biometric sensor during biometric authentication, in accordance with some examples. 
         FIGS. 41A-41C  are flow diagrams illustrating a method for providing indications about the biometric sensor during biometric authentication, in accordance with some examples. 
         FIGS. 42A-42P  illustrate exemplary user interfaces for orienting the device to enroll a biometric feature, in accordance with some examples 
         FIGS. 43A-43C  are flow diagrams illustrating a method for orienting the device to enroll a biometric feature, in accordance with some examples. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following description sets forth exemplary methods, parameters, and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure but is instead provided as a description of exemplary embodiments. 
     There is a need for electronic devices that provide efficient methods and interfaces for implementing biometric authentication of biometric features. For example, there is a need for electronic devices that provide a convenient and efficient method for enrolling one or more portions of a biometric feature. For another example, there is a need for electronic devices that provide a quick and intuitive technique for selectively accessing secure data in accordance with biometric authentication. For another example, there is a need for electronic devices that provide a quick and intuitive technique for enabling a function of a device in accordance with biometric authentication. Such techniques can reduce the cognitive burden on a user who enrolls a biometric feature and/or biometrically authenticates with a device, thereby enhancing overall productivity. Further, such techniques can reduce processor and battery power otherwise wasted on redundant user inputs. 
     Below,  FIGS. 1A-1C, 2, 3, 4A-4B, and 5A-5H  provide a description of exemplary devices for performing the techniques for implementing biometric authentication.  FIG. 6  illustrates exemplary devices connected via one or more communication channels, in accordance with some embodiments.  FIGS. 7A-7S  illustrate exemplary user interfaces for a biometric enrollment process tutorial, in accordance with some embodiments.  FIGS. 8A-8C  are a flow diagram illustrating methods of a biometric enrollment process tutorial. The user interfaces in  FIGS. 7A-7S  are used to illustrate the processes described below, including the processes in  FIGS. 8A-8C .  FIGS. 9A-9AE  illustrate exemplary user interfaces for aligning a biometric feature for enrollment.  FIGS. 10A-10F  are a flow diagram illustrating methods of aligning a biometric feature for enrollment. The user interfaces in  FIGS. 9A-9AE  are used to illustrate the processes described below, including the processes in  FIGS. 10A-10F .  FIGS. 11A-11O  illustrate exemplary user interfaces for enrolling a biometric feature.  FIGS. 12A-12B  are a flow diagram illustrating methods of enrolling a biometric feature. The user interfaces in  FIGS. 11A-11O  are used to illustrate the processes described below, including the processes in  FIGS. 12A-12B .  FIGS. 13A-13R  illustrate exemplary user interfaces for providing hints during a biometric enrollment process.  FIGS. 14A-14C  are a flow diagram illustrating methods of providing hints during a biometric enrollment process. The user interfaces in  FIGS. 13A-13R  are used to illustrate the processes described below, including the processes in  FIGS. 14A-14C .  FIGS. 15A-15T  illustrate exemplary user interfaces for application-based biometric authentication.  FIGS. 16A-16E  are a flow diagram illustrating methods of application-based biometric authentication. The user interfaces in  FIGS. 15A-15T  are used to illustrate the processes described below, including the processes in  FIGS. 16A-16E .  FIGS. 17A-17AI  illustrate exemplary user interfaces for autofilling biometrically secured fields.  FIGS. 18A-18D  are a flow diagram illustrating methods of autofilling biometrically secured fields. The user interfaces in  FIGS. 17A-17AI  are used to illustrate the processes described below, including the processes in  FIGS. 18A-18D .  FIGS. 19A-19AB  illustrate exemplary user interfaces for unlocking a device using biometric authentication.  FIGS. 20A-20F  are a flow diagram illustrating methods of unlocking a device using biometric authentication. The user interfaces in  FIGS. 19A-19AB  are used to illustrate the processes described below, including the processes in  FIGS. 20A-20F .  FIGS. 21A-21AQ  illustrate exemplary user interfaces for retrying biometric authentication  FIGS. 22A-22F  are a flow diagram illustrating methods of for retrying biometric authentication. The user interfaces in  FIGS. 21A-21AQ  are used to illustrate the processes described below, including the processes in  FIGS. 22A-22F .  FIGS. 23A-23Q  illustrate exemplary user interfaces for managing transfers using biometric authentication.  FIGS. 24A-24BC  illustrate exemplary user interfaces for managing transfers using biometric authentication.  FIGS. 25A-25C  are a flow diagram illustrating methods of managing transfers using biometric authentication. The user interfaces in  FIGS. 23A-23Q  and  FIGS. 24A-24BC  are used to illustrate the processes described below, including the processes in  FIGS. 25A-25C .  FIGS. 26A-26AS  illustrate exemplary user interfaces for providing interstitial user interfaces during biometric authentication.  FIGS. 27A-27E  are a flow diagram illustrating methods of providing interstitial user interfaces during biometric authentication. The user interfaces in  FIGS. 26A-26AS  are used to illustrate the processes described below, including the processes in  FIGS. 27A-27E .  FIGS. 28A-28AA  illustrate exemplary user interfaces for preventing retrying biometric authentication.  FIGS. 29A-29B  are a flow diagram illustrating methods of preventing retrying biometric authentication. The user interfaces in  FIGS. 28A-28AA  are used to illustrate the processes described below, including the processes in  FIGS. 29A-29B .  FIGS. 30A-30AL  illustrate exemplary user interfaces for cached biometric authentication.  FIGS. 31A-31B  are a flow diagram illustrating methods of cached biometric authentication. The user interfaces in  FIGS. 30A-30AL  are used to illustrate the processes described below, including the processes in  FIGS. 31A-31B .  FIGS. 32A-32W  illustrate exemplary user interfaces for autofilling fillable fields based on visibility criteria.  FIG. 33  is a flow diagram illustrating methods of autofilling fillable fields based on visibility criteria. The user interfaces in  FIGS. 32A-32W  are used to illustrate the processes described below, including the processes in  FIG. 33 .  FIGS. 34A-34N  illustrate exemplary user interfaces for automatic log-in using biometric authentication.  FIG. 35  is a flow diagram illustrating methods of automatic log-in using biometric authentication. The user interfaces in  FIGS. 34A-34N  are used to illustrate the processes described below, including the processes in  FIG. 35 .  FIGS. 36A-36L  illustrate exemplary user interfaces for retrying biometric authentication at a credential entry user interface.  FIGS. 37A-37B  are flow diagrams illustrating a method for retrying biometric authentication at a credential entry user interface. The user interfaces in  FIGS. 36A-36L  are used to illustrate the processes described below, including the processes in  FIGS. 37A-37B .  FIGS. 38A-38AD  illustrate exemplary user interfaces for providing indications of error conditions during biometric authentication.  FIGS. 39A-39B  are flow diagrams illustrating a method for providing indications of error conditions during biometric authentication. The user interfaces in  FIGS. 38A-38AD  are used to illustrate the processes described below, including the processes in  FIGS. 39A-39B .  FIGS. 40A-40U  illustrate exemplary user interfaces for providing indications about the biometric sensor during biometric authentication.  FIGS. 41A-41C  are flow diagrams illustrating a method for providing indications about the biometric sensor during biometric authentication. The user interfaces in  FIGS. 40A-40U  are used to illustrate the processes described below, including the processes in  FIGS. 41A-41C .  FIGS. 42A-42P  illustrate exemplary user interfaces for orienting the device to enroll a biometric feature.  FIGS. 43A-43C  are flow diagrams illustrating a method for orienting the device to enroll a biometric feature. The user interfaces in  FIGS. 42A-42P  are used to illustrate the processes described below, including the processes in  FIGS. 43A-43C . 
     Although the following description uses terms “first,” “second,” etc. to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another. For example, a first touch could be termed a second touch, and, similarly, a second touch could be termed a first touch, without departing from the scope of the various described embodiments. The first touch and the second touch are both touches, but they are not the same touch. 
     The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various described embodiments and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     The term “if” is, optionally, construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. Similarly, the phrase “if it is determined” or “if [a stated condition or event] is detected” is, optionally, construed to mean “upon determining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event],” depending on the context. 
     Embodiments of electronic devices, user interfaces for such devices, and associated processes for using such devices are described. In some embodiments, the device is a portable communications device, such as a mobile telephone, that also contains other functions, such as PDA and/or music player functions. Exemplary embodiments of portable multifunction devices include, without limitation, the iPhone®, iPod Touch®, and iPad® devices from Apple Inc. of Cupertino, Calif. Other portable electronic devices, such as laptops or tablet computers with touch-sensitive surfaces (e.g., touch screen displays and/or touchpads), are, optionally, used. It should also be understood that, in some embodiments, the device is not a portable communications device, but is a desktop computer with a touch-sensitive surface (e.g., a touch screen display and/or a touchpad). 
     In the discussion that follows, an electronic device that includes a display and a touch-sensitive surface is described. It should be understood, however, that the electronic device optionally includes one or more other physical user-interface devices, such as a physical keyboard, a mouse, and/or a joystick. 
     The device typically supports a variety of applications, such as one or more of the following: a drawing application, a presentation application, a word processing application, a website creation application, a disk authoring application, a spreadsheet application, a gaming application, a telephone application, a video conferencing application, an e-mail application, an instant messaging application, a workout support application, a photo management application, a digital camera application, a digital video camera application, a web browsing application, a digital music player application, and/or a digital video player application. 
     The various applications that are executed on the device optionally use at least one common physical user-interface device, such as the touch-sensitive surface. One or more functions of the touch-sensitive surface as well as corresponding information displayed on the device are, optionally, adjusted and/or varied from one application to the next and/or within a respective application. In this way, a common physical architecture (such as the touch-sensitive surface) of the device optionally supports the variety of applications with user interfaces that are intuitive and transparent to the user. 
     Attention is now directed toward embodiments of portable devices with touch-sensitive displays.  FIG. 1A  is a block diagram illustrating portable multifunction device  100  with touch-sensitive display system  112  in accordance with some embodiments. Touch-sensitive display  112  is sometimes called a “touch screen” for convenience and is sometimes known as or called a “touch-sensitive display system.” Device  100  includes memory  102  (which optionally includes one or more computer-readable storage mediums), memory controller  122 , one or more processing units (CPUs)  120 , peripherals interface  118 , RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , input/output (I/O) subsystem  106 , other input control devices  116 , and external port  124 . Device  100  optionally includes one or more optical sensors  164 . Device  100  optionally includes one or more contact intensity sensors  165  for detecting intensity of contacts on device  100  (e.g., a touch-sensitive surface such as touch-sensitive display system  112  of device  100 ). Device  100  optionally includes one or more tactile output generators  167  for generating tactile outputs on device  100  (e.g., generating tactile outputs on a touch-sensitive surface such as touch-sensitive display system  112  of device  100  or touchpad  355  of device  300 ). These components optionally communicate over one or more communication buses or signal lines  103 . 
     As used in the specification and claims, the term “intensity” of a contact on a touch-sensitive surface refers to the force or pressure (force per unit area) of a contact (e.g., a finger contact) on the touch-sensitive surface, or to a substitute (proxy) for the force or pressure of a contact on the touch-sensitive surface. The intensity of a contact has a range of values that includes at least four distinct values and more typically includes hundreds of distinct values (e.g., at least 256). Intensity of a contact is, optionally, determined (or measured) using various approaches and various sensors or combinations of sensors. For example, one or more force sensors underneath or adjacent to the touch-sensitive surface are, optionally, used to measure force at various points on the touch-sensitive surface. In some implementations, force measurements from multiple force sensors are combined (e.g., a weighted average) to determine an estimated force of a contact. Similarly, a pressure-sensitive tip of a stylus is, optionally, used to determine a pressure of the stylus on the touch-sensitive surface. Alternatively, the size of the contact area detected on the touch-sensitive surface and/or changes thereto, the capacitance of the touch-sensitive surface proximate to the contact and/or changes thereto, and/or the resistance of the touch-sensitive surface proximate to the contact and/or changes thereto are, optionally, used as a substitute for the force or pressure of the contact on the touch-sensitive surface. In some implementations, the substitute measurements for contact force or pressure are used directly to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is described in units corresponding to the substitute measurements). In some implementations, the substitute measurements for contact force or pressure are converted to an estimated force or pressure, and the estimated force or pressure is used to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is a pressure threshold measured in units of pressure). Using the intensity of a contact as an attribute of a user input allows for user access to additional device functionality that is, in some circumstances, otherwise not be accessible by the user on a reduced-size device with limited real estate for displaying affordances (e.g., on a touch-sensitive display) and/or receiving user input (e.g., via a touch-sensitive display, a touch-sensitive surface, or a physical/mechanical control such as a knob or a button). 
     As used in the specification and claims, the term “tactile output” refers to physical displacement of a device relative to a previous position of the device, physical displacement of a component (e.g., a touch-sensitive surface) of a device relative to another component (e.g., housing) of the device, or displacement of the component relative to a center of mass of the device that will be detected by a user with the user&#39;s sense of touch. For example, in situations where the device or the component of the device is in contact with a surface of a user that is sensitive to touch (e.g., a finger, palm, or other part of a user&#39;s hand), the tactile output generated by the physical displacement will be interpreted by the user as a tactile sensation corresponding to a perceived change in physical characteristics of the device or the component of the device. For example, movement of a touch-sensitive surface (e.g., a touch-sensitive display or trackpad) is, optionally, interpreted by the user as a “down click” or “up click” of a physical actuator button. In some cases, a user will feel a tactile sensation such as an “down click” or “up click” even when there is no movement of a physical actuator button associated with the touch-sensitive surface that is physically pressed (e.g., displaced) by the user&#39;s movements. As another example, movement of the touch-sensitive surface is, optionally, interpreted or sensed by the user as “roughness” of the touch-sensitive surface, even when there is no change in smoothness of the touch-sensitive surface. While such interpretations of touch by a user will be subject to the individualized sensory perceptions of the user, there are many sensory perceptions of touch that are common to a large majority of users. Thus, when a tactile output is described as corresponding to a particular sensory perception of a user (e.g., an “up click,” a “down click,” “roughness”), unless otherwise stated, the generated tactile output corresponds to physical displacement of the device or a component thereof that will generate the described sensory perception for a typical (or average) user. Using tactile outputs to provide haptic feedback to a user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some embodiments, a tactile output pattern specifies characteristics of a tactile output, such as the amplitude of the tactile output, the shape of a movement waveform of the tactile output, the frequency of the tactile output, and/or the duration of the tactile output. 
     When tactile outputs with different tactile output patterns are generated by a device (e.g., via one or more tactile output generators that move a moveable mass to generate tactile outputs), the tactile outputs can invoke different haptic sensations in a user holding or touching the device. While the sensation of the user is based on the user&#39;s perception of the tactile output, most users will be able to identify changes in waveform, frequency, and amplitude of tactile outputs generated by the device. Thus, the waveform, frequency and amplitude can be adjusted to indicate to the user that different operations have been performed. As such, tactile outputs with tactile output patterns that are designed, selected, and/or engineered to simulate characteristics (e.g., size, material, weight, stiffness, smoothness, etc.); behaviors (e.g., oscillation, displacement, acceleration, rotation, expansion, etc.); and/or interactions (e.g., collision, adhesion, repulsion, attraction, friction, etc.) of objects in a given environment (e.g., a user interface that includes graphical features and objects, a simulated physical environment with virtual boundaries and virtual objects, a real physical environment with physical boundaries and physical objects, and/or a combination of any of the above) will, in some circumstances, provide helpful feedback to users that reduces input errors and increases the efficiency of the user&#39;s operation of the device. Additionally, tactile outputs are, optionally, generated to correspond to feedback that is unrelated to a simulated physical characteristic, such as an input threshold or a selection of an object. Such tactile outputs will, in some circumstances, provide helpful feedback to users that reduces input errors and increases the efficiency of the user&#39;s operation of the device. 
     In some embodiments, a tactile output with a suitable tactile output pattern serves as a cue for the occurrence of an event of interest in a user interface or behind the scenes in a device. Examples of the events of interest include activation of an affordance (e.g., a real or virtual button, or toggle switch) provided on the device or in a user interface, success or failure of a requested operation, reaching or crossing a boundary in a user interface, entry into a new state, switching of input focus between objects, activation of a new mode, reaching or crossing an input threshold, detection or recognition of a type of input or gesture, etc. In some embodiments, tactile outputs are provided to serve as a warning or an alert for an impending event or outcome that would occur unless a redirection or interruption input is timely detected. Tactile outputs are also used in other contexts to enrich the user experience, improve the accessibility of the device to users with visual or motor difficulties or other accessibility needs, and/or improve efficiency and functionality of the user interface and/or the device. Tactile outputs are optionally accompanied with audio outputs and/or visible user interface changes, which further enhance a user&#39;s experience when the user interacts with a user interface and/or the device, and facilitate better conveyance of information regarding the state of the user interface and/or the device, and which reduce input errors and increase the efficiency of the user&#39;s operation of the device. 
       FIGS. 4C-4E  provide a set of sample tactile output patterns that can be used, either individually or in combination, either as is or through one or more transformations (e.g., modulation, amplification, truncation, etc.), to create suitable haptic feedback in various scenarios and for various purposes, such as those mentioned above and those described with respect to the user interfaces and methods discussed herein. This example of a palette of tactile outputs shows how a set of three waveforms and eight frequencies can be used to produce an array of tactile output patterns. In addition to the tactile output patterns shown in this figure, each of these tactile output patterns is optionally adjusted in amplitude by changing a gain value for the tactile output pattern, as shown, for example for FullTap 80 Hz, FullTap 200 Hz, MiniTap 80 Hz, MiniTap 200 Hz, MicroTap 80 Hz, and MicroTap 200 Hz in  FIGS. 4F-4H , which are each shown with variants having a gain of 1.0, 0.75, 0.5, and 0.25. As shown in  FIGS. 4F-4H , changing the gain of a tactile output pattern changes the amplitude of the pattern without changing the frequency of the pattern or changing the shape of the waveform. In some embodiments, changing the frequency of a tactile output pattern also results in a lower amplitude as some tactile output generators are limited by how much force can be applied to the moveable mass and thus higher frequency movements of the mass are constrained to lower amplitudes to ensure that the acceleration needed to create the waveform does not require force outside of an operational force range of the tactile output generator (e.g., the peak amplitudes of the FullTap at 230 Hz, 270 Hz, and 300 Hz are lower than the amplitudes of the FullTap at 80 Hz, 100 Hz, 125 Hz, and 200 Hz). 
       FIGS. 4C-4H  show tactile output patterns that have a particular waveform. The waveform of a tactile output pattern represents the pattern of physical displacements relative to a neutral position (e.g., xzero) versus time that an moveable mass goes through to generate a tactile output with that tactile output pattern. For example, a first set of tactile output patterns shown in  FIG. 4C  (e.g., tactile output patterns of a “FullTap”) each have a waveform that includes an oscillation with two complete cycles (e.g., an oscillation that starts and ends in a neutral position and crosses the neutral position three times). A second set of tactile output patterns shown in  FIG. 4D  (e.g., tactile output patterns of a “MiniTap”) each have a waveform that includes an oscillation that includes one complete cycle (e.g., an oscillation that starts and ends in a neutral position and crosses the neutral position one time). A third set of tactile output patterns shown in  FIG. 4E  (e.g., tactile output patterns of a “MicroTap”) each have a waveform that includes an oscillation that include one half of a complete cycle (e.g., an oscillation that starts and ends in a neutral position and does not cross the neutral position). The waveform of a tactile output pattern also includes a start buffer and an end buffer that represent the gradual speeding up and slowing down of the moveable mass at the start and at the end of the tactile output. The example waveforms shown in  FIGS. 4C-4H  include xmin and xmax values which represent the maximum and minimum extent of movement of the moveable mass. For larger electronic devices with larger moveable masses, there can be larger or smaller minimum and maximum extents of movement of the mass. The examples shown in  FIGS. 4C-4H  describe movement of a mass in 1 dimension, however similar principles would also apply to movement of a moveable mass in two or three dimensions. 
     As shown in  FIGS. 4C-4E , each tactile output pattern also has a corresponding characteristic frequency that affects the “pitch” of a haptic sensation that is felt by a user from a tactile output with that characteristic frequency. For a continuous tactile output, the characteristic frequency represents the number of cycles that are completed within a given period of time (e.g., cycles per second) by the moveable mass of the tactile output generator. For a discrete tactile output, a discrete output signal (e.g., with 0.5, 1, or 2 cycles) is generated, and the characteristic frequency value specifies how fast the moveable mass needs to move to generate a tactile output with that characteristic frequency. As shown in  FIGS. 4C-4H , for each type of tactile output (e.g., as defined by a respective waveform, such as FullTap, MiniTap, or MicroTap), a higher frequency value corresponds to faster movement(s) by the moveable mass, and hence, in general, a shorter time to complete the tactile output (e.g., including the time to complete the required number of cycle(s) for the discrete tactile output, plus a start and an end buffer time). For example, a FullTap with a characteristic frequency of 80 Hz takes longer to complete than FullTap with a characteristic frequency of 100 Hz (e.g., 35.4 ms vs. 28.3 ms in  FIG. 4C ). In addition, for a given frequency, a tactile output with more cycles in its waveform at a respective frequency takes longer to complete than a tactile output with fewer cycles its waveform at the same respective frequency. For example, a FullTap at 150 Hz takes longer to complete than a MiniTap at 150 Hz (e.g., 19.4 ms vs. 12.8 ms), and a MiniTap at 150 Hz takes longer to complete than a MicroTap at 150 Hz (e.g., 12.8 ms vs. 9.4 ms). However, for tactile output patterns with different frequencies this rule may not apply (e.g., tactile outputs with more cycles but a higher frequency can take a shorter amount of time to complete than tactile outputs with fewer cycles but a lower frequency, and vice versa). For example, at 300 Hz, a FullTap takes as long as a MiniTap (e.g., 9.9 ms). 
     As shown in  FIGS. 4C-4E , a tactile output pattern also has a characteristic amplitude that affects the amount of energy that is contained in a tactile signal, or a “strength” of a haptic sensation that can be felt by a user through a tactile output with that characteristic amplitude. In some embodiments, the characteristic amplitude of a tactile output pattern refers to an absolute or normalized value that represents the maximum displacement of the moveable mass from a neutral position when generating the tactile output. In some embodiments, the characteristic amplitude of a tactile output pattern is adjustable, e.g., by a fixed or dynamically determined gain factor (e.g., a value between 0 and 1), in accordance with various conditions (e.g., customized based on user interface contexts and behaviors) and/or preconfigured metrics (e.g., input-based metrics, and/or user-interface-based metrics). In some embodiments, an input-based metric (e.g., an intensity-change metric or an input-speed metric) measures a characteristic of an input (e.g., a rate of change of a characteristic intensity of a contact in a press input or a rate of movement of the contact across a touch-sensitive surface) during the input that triggers generation of a tactile output. In some embodiments, a user-interface-based metric (e.g., a speed-across-boundary metric) measures a characteristic of a user interface element (e.g., a speed of movement of the element across a hidden or visible boundary in a user interface) during the user interface change that triggers generation of the tactile output. In some embodiments, the characteristic amplitude of a tactile output pattern can be modulated by an “envelope” and the peaks of adjacent cycles can have different amplitudes, where one of the waveforms shown above is further modified by multiplication by an envelope parameter that changes over time (e.g., from 0 to 1) to gradually adjust amplitude of portions of the tactile output over time as the tactile output is being generated. 
     Although specific frequencies, amplitudes, and waveforms are represented in the sample tactile output patterns in  FIGS. 4C-4E  for illustrative purposes, tactile output patterns with other frequencies, amplitudes, and waveforms can be used for similar purposes. For example, waveforms that have between 0.5 to 4 cycles can be used. Other frequencies in the range of 60 Hz-400 Hz can be used as well. Table 1 provides examples of particular haptic feedback behaviors, configurations, and examples of their use. 
     It should be appreciated that device  100  is only one example of a portable multifunction device, and that device  100  optionally has more or fewer components than shown, optionally combines two or more components, or optionally has a different configuration or arrangement of the components. The various components shown in  FIG. 1A  are implemented in hardware, software, or a combination of both hardware and software, including one or more signal processing and/or application-specific integrated circuits. 
     Memory  102  optionally includes high-speed random access memory and optionally also includes non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices. Memory controller  122  optionally controls access to memory  102  by other components of device  100 . 
     Peripherals interface  118  can be used to couple input and output peripherals of the device to CPU  120  and memory  102 . The one or more processors  120  run or execute various software programs and/or sets of instructions stored in memory  102  to perform various functions for device  100  and to process data. In some embodiments, peripherals interface  118 , CPU  120 , and memory controller  122  are, optionally, implemented on a single chip, such as chip  104 . In some other embodiments, they are, optionally, implemented on separate chips. 
     RF (radio frequency) circuitry  108  receives and sends RF signals, also called electromagnetic signals. RF circuitry  108  converts electrical signals to/from electromagnetic signals and communicates with communications networks and other communications devices via the electromagnetic signals. RF circuitry  108  optionally includes well-known circuitry for performing these functions, including but not limited to an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC chipset, a subscriber identity module (SIM) card, memory, and so forth. RF circuitry  108  optionally communicates with networks, such as the Internet, also referred to as the World Wide Web (WWW), an intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN), and other devices by wireless communication. The RF circuitry  108  optionally includes well-known circuitry for detecting near field communication (NFC) fields, such as by a short-range communication radio. The wireless communication optionally uses any of a plurality of communications standards, protocols, and technologies, including but not limited to Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), high-speed downlink packet access (HSDPA), high-speed uplink packet access (HSUPA), Evolution, Data-Only (EV-DO), HSPA, HSPA+, Dual-Cell HSPA (DC-HSPDA), long term evolution (LTE), near field communication (NFC), wideband code division multiple access (W-CDMA), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Bluetooth Low Energy (BTLE), Wireless Fidelity (Wi-Fi) (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, and/or IEEE 802.11ac), voice over Internet Protocol (VoIP), Wi-MAX, a protocol for e-mail (e.g., Internet message access protocol (IMAP) and/or post office protocol (POP)), instant messaging (e.g., extensible messaging and presence protocol (XMPP), Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions (SIMPLE), Instant Messaging and Presence Service (IMPS)), and/or Short Message Service (SMS), or any other suitable communication protocol, including communication protocols not yet developed as of the filing date of this document. 
     Audio circuitry  110 , speaker  111 , and microphone  113  provide an audio interface between a user and device  100 . Audio circuitry  110  receives audio data from peripherals interface  118 , converts the audio data to an electrical signal, and transmits the electrical signal to speaker  111 . Speaker  111  converts the electrical signal to human-audible sound waves. Audio circuitry  110  also receives electrical signals converted by microphone  113  from sound waves. Audio circuitry  110  converts the electrical signal to audio data and transmits the audio data to peripherals interface  118  for processing. Audio data is, optionally, retrieved from and/or transmitted to memory  102  and/or RF circuitry  108  by peripherals interface  118 . In some embodiments, audio circuitry  110  also includes a headset jack (e.g.,  212 ,  FIG. 2 ). The headset jack provides an interface between audio circuitry  110  and removable audio input/output peripherals, such as output-only headphones or a headset with both output (e.g., a headphone for one or both ears) and input (e.g., a microphone). 
     I/O subsystem  106  couples input/output peripherals on device  100 , such as touch screen  112  and other input control devices  116 , to peripherals interface  118 . I/O subsystem  106  optionally includes display controller  156 , optical sensor controller  158 , intensity sensor controller  159 , haptic feedback controller  161 , depth camera controller  169 , and one or more input controllers  160  for other input or control devices. The one or more input controllers  160  receive/send electrical signals from/to other input control devices  116 . The other input control devices  116  optionally include physical buttons (e.g., push buttons, rocker buttons, etc.), dials, slider switches, joysticks, click wheels, and so forth. In some alternate embodiments, input controller(s)  160  are, optionally, coupled to any (or none) of the following: a keyboard, an infrared port, a USB port, and a pointer device such as a mouse. The one or more buttons (e.g.,  208 ,  FIG. 2 ) optionally include an up/down button for volume control of speaker  111  and/or microphone  113 . The one or more buttons optionally include a push button (e.g.,  206 ,  FIG. 2 ). 
     A quick press of the push button optionally disengages a lock of touch screen  112  or optionally begins a process that uses gestures on the touch screen to unlock the device, as described in U.S. patent application Ser. No. 11/322,549, “Unlocking a Device by Performing Gestures on an Unlock Image,” filed Dec. 23, 2005, U.S. Pat. No. 7,657,849, which is hereby incorporated by reference in its entirety. A longer press of the push button (e.g.,  206 ) optionally turns power to device  100  on or off. The functionality of one or more of the buttons are, optionally, user-customizable. Touch screen  112  is used to implement virtual or soft buttons and one or more soft keyboards. 
     Touch-sensitive display  112  provides an input interface and an output interface between the device and a user. Display controller  156  receives and/or sends electrical signals from/to touch screen  112 . Touch screen  112  displays visual output to the user. The visual output optionally includes graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). In some embodiments, some or all of the visual output optionally corresponds to user-interface objects. 
     Touch screen  112  has a touch-sensitive surface, sensor, or set of sensors that accepts input from the user based on haptic and/or tactile contact. Touch screen  112  and display controller  156  (along with any associated modules and/or sets of instructions in memory  102 ) detect contact (and any movement or breaking of the contact) on touch screen  112  and convert the detected contact into interaction with user-interface objects (e.g., one or more soft keys, icons, web pages, or images) that are displayed on touch screen  112 . In an exemplary embodiment, a point of contact between touch screen  112  and the user corresponds to a finger of the user. 
     Touch screen  112  optionally uses LCD (liquid crystal display) technology, LPD (light emitting polymer display) technology, or LED (light emitting diode) technology, although other display technologies are used in other embodiments. Touch screen  112  and display controller  156  optionally detect contact and any movement or breaking thereof using any of a plurality of touch sensing technologies now known or later developed, including but not limited to capacitive, resistive, infrared, and surface acoustic wave technologies, as well as other proximity sensor arrays or other elements for determining one or more points of contact with touch screen  112 . In an exemplary embodiment, projected mutual capacitance sensing technology is used, such as that found in the iPhone® and iPod Touch® from Apple Inc. of Cupertino, Calif. 
     A touch-sensitive display in some embodiments of touch screen  112  is, optionally, analogous to the multi-touch sensitive touchpads described in the following U.S. Pat. No. 6,323,846 (Westerman et al.), U.S. Pat. No. 6,570,557 (Westerman et al.), and/or U.S. Pat. No. 6,677,932 (Westerman), and/or U.S. Patent Publication 2002/0015024A1, each of which is hereby incorporated by reference in its entirety. However, touch screen  112  displays visual output from device  100 , whereas touch-sensitive touchpads do not provide visual output. 
     A touch-sensitive display in some embodiments of touch screen  112  is described in the following applications: (1) U.S. patent application Ser. No. 11/381,313, “Multipoint Touch Surface Controller,” filed May 2, 2006; (2) U.S. patent application Ser. No. 10/840,862, “Multipoint Touchscreen,” filed May 6, 2004; (3) U.S. patent application Ser. No. 10/903,964, “Gestures For Touch Sensitive Input Devices,” filed Jul. 30, 2004; (4) U.S. patent application Ser. No. 11/048,264, “Gestures For Touch Sensitive Input Devices,” filed Jan. 31, 2005; (5) U.S. patent application Ser. No. 11/038,590, “Mode-Based Graphical User Interfaces For Touch Sensitive Input Devices,” filed Jan. 18, 2005; (6) U.S. patent application Ser. No. 11/228,758, “Virtual Input Device Placement On A Touch Screen User Interface,” filed Sep. 16, 2005; (7) U.S. patent application Ser. No. 11/228,700, “Operation Of A Computer With A Touch Screen Interface,” filed Sep. 16, 2005; (8) U.S. patent application Ser. No. 11/228,737, “Activating Virtual Keys Of A Touch-Screen Virtual Keyboard,” filed Sep. 16, 2005; and (9) U.S. patent application Ser. No. 11/367,749, “Multi-Functional Hand-Held Device,” filed Mar. 3, 2006. All of these applications are incorporated by reference herein in their entirety. 
     Touch screen  112  optionally has a video resolution in excess of 100 dpi. In some embodiments, the touch screen has a video resolution of approximately 160 dpi. The user optionally makes contact with touch screen  112  using any suitable object or appendage, such as a stylus, a finger, and so forth. In some embodiments, the user interface is designed to work primarily with finger-based contacts and gestures, which can be less precise than stylus-based input due to the larger area of contact of a finger on the touch screen. In some embodiments, the device translates the rough finger-based input into a precise pointer/cursor position or command for performing the actions desired by the user. 
     In some embodiments, in addition to the touch screen, device  100  optionally includes a touchpad (not shown) for activating or deactivating particular functions. In some embodiments, the touchpad is a touch-sensitive area of the device that, unlike the touch screen, does not display visual output. The touchpad is, optionally, a touch-sensitive surface that is separate from touch screen  112  or an extension of the touch-sensitive surface formed by the touch screen. 
     Device  100  also includes power system  162  for powering the various components. Power system  162  optionally includes a power management system, one or more power sources (e.g., battery, alternating current (AC)), a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator (e.g., a light-emitting diode (LED)) and any other components associated with the generation, management and distribution of power in portable devices. 
     Device  100  optionally also includes one or more optical sensors  164 .  FIG. 1A  shows an optical sensor coupled to optical sensor controller  158  in I/O subsystem  106 . Optical sensor  164  optionally includes charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) phototransistors. Optical sensor  164  receives light from the environment, projected through one or more lenses, and converts the light to data representing an image. In conjunction with imaging module  143  (also called a camera module), optical sensor  164  optionally captures still images or video. In some embodiments, an optical sensor is located on the back of device  100 , opposite touch screen display  112  on the front of the device so that the touch screen display is enabled for use as a viewfinder for still and/or video image acquisition. In some embodiments, an optical sensor is located on the front of the device so that the user&#39;s image is, optionally, obtained for video conferencing while the user views the other video conference participants on the touch screen display. In some embodiments, the position of optical sensor  164  can be changed by the user (e.g., by rotating the lens and the sensor in the device housing) so that a single optical sensor  164  is used along with the touch screen display for both video conferencing and still and/or video image acquisition. 
     Device  100  optionally also includes one or more contact intensity sensors  165 .  FIG. 1A  shows a contact intensity sensor coupled to intensity sensor controller  159  in I/O subsystem  106 . Contact intensity sensor  165  optionally includes one or more piezoresistive strain gauges, capacitive force sensors, electric force sensors, piezoelectric force sensors, optical force sensors, capacitive touch-sensitive surfaces, or other intensity sensors (e.g., sensors used to measure the force (or pressure) of a contact on a touch-sensitive surface). Contact intensity sensor  165  receives contact intensity information (e.g., pressure information or a proxy for pressure information) from the environment. In some embodiments, at least one contact intensity sensor is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system  112 ). In some embodiments, at least one contact intensity sensor is located on the back of device  100 , opposite touch screen display  112 , which is located on the front of device  100 . 
     Device  100  optionally also includes one or more proximity sensors  166 .  FIG. 1A  shows proximity sensor  166  coupled to peripherals interface  118 . Alternately, proximity sensor  166  is, optionally, coupled to input controller  160  in I/O subsystem  106 . Proximity sensor  166  optionally performs as described in U.S. patent application Ser. No. 11/241,839, “Proximity Detector In Handheld Device”; Ser. No. 11/240,788, “Proximity Detector In Handheld Device”; Ser. No. 11/620,702, “Using Ambient Light Sensor To Augment Proximity Sensor Output”; Ser. No. 11/586,862, “Automated Response To And Sensing Of User Activity In Portable Devices”; and Ser. No. 11/638,251, “Methods And Systems For Automatic Configuration Of Peripherals,” which are hereby incorporated by reference in their entirety. In some embodiments, the proximity sensor turns off and disables touch screen  112  when the multifunction device is placed near the user&#39;s ear (e.g., when the user is making a phone call). 
     Device  100  optionally also includes one or more tactile output generators  167 .  FIG. 1A  shows a tactile output generator coupled to haptic feedback controller  161  in I/O subsystem  106 . Tactile output generator  167  optionally includes one or more electroacoustic devices such as speakers or other audio components and/or electromechanical devices that convert energy into linear motion such as a motor, solenoid, electroactive polymer, piezoelectric actuator, electrostatic actuator, or other tactile output generating component (e.g., a component that converts electrical signals into tactile outputs on the device). Contact intensity sensor  165  receives tactile feedback generation instructions from haptic feedback module  133  and generates tactile outputs on device  100  that are capable of being sensed by a user of device  100 . In some embodiments, at least one tactile output generator is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system  112 ) and, optionally, generates a tactile output by moving the touch-sensitive surface vertically (e.g., in/out of a surface of device  100 ) or laterally (e.g., back and forth in the same plane as a surface of device  100 ). In some embodiments, at least one tactile output generator sensor is located on the back of device  100 , opposite touch screen display  112 , which is located on the front of device  100 . 
     Device  100  optionally also includes one or more accelerometers  168 .  FIG. 1A  shows accelerometer  168  coupled to peripherals interface  118 . Alternately, accelerometer  168  is, optionally, coupled to an input controller  160  in I/O subsystem  106 . Accelerometer  168  optionally performs as described in U.S. Patent Publication No. 20050190059, “Acceleration-based Theft Detection System for Portable Electronic Devices,” and U.S. Patent Publication No. 20060017692, “Methods And Apparatuses For Operating A Portable Device Based On An Accelerometer,” both of which are incorporated by reference herein in their entirety. In some embodiments, information is displayed on the touch screen display in a portrait view or a landscape view based on an analysis of data received from the one or more accelerometers. Device  100  optionally includes, in addition to accelerometer(s)  168 , a magnetometer (not shown) and a GPS (or GLONASS or other global navigation system) receiver (not shown) for obtaining information concerning the location and orientation (e.g., portrait or landscape) of device  100 . 
     In some embodiments, device  100  also includes (or is in communication with) one or more fingerprint sensors. The one or more fingerprint sensors are coupled to peripherals interface  118 . Alternately, the one or more fingerprint sensors are, optionally, coupled to an input controller  160  in I/O subsystem  106 . However, in one common embodiment, fingerprint identification operations are performed using secured dedicated computing hardware (e.g., one or more processors, memory and/or communications busses) that has additional security features so as to enhance security of the fingerprint information determined by the one or more fingerprint sensors. As used herein, a fingerprint sensor is a sensor that is capable of distinguishing fingerprint features (sometimes called “minutia features”) of the ridges and valleys of skin such as those found on the fingers and toes of humans. A fingerprint sensor can use any of a variety of techniques to distinguish the fingerprint features, including but not limited to: optical fingerprint imaging, ultrasonic fingerprint imaging, active capacitance fingerprint imaging and passive capacitance fingerprint imaging. In addition to distinguishing fingerprint features in fingerprints, in some embodiments, the one or more fingerprint sensors are capable of tracking movement of fingerprint features over time and thereby determining/characterizing movement of the fingerprint over time on the one or more fingerprint sensors. While the one or more fingerprint sensors can be separate from the touch-sensitive surface (e.g., Touch-Sensitive Display System  112 ), it should be understood that in some implementations, the touch-sensitive surface (e.g., Touch-Sensitive Display System  112 ) has a spatial resolution that is high enough to detect fingerprint features formed by individual fingerprint ridges and is used as a fingerprint sensor instead of, or in addition to, the one or more fingerprint sensors. In some embodiments, device  100  includes a set of one or more orientation sensors that are used to determine an orientation of a finger or hand on or proximate to the device (e.g., an orientation of a finger that is over one or more fingerprint sensors). Additionally, in some embodiments, the set of one or more orientation sensors are used in addition to or instead of a fingerprint sensor to detect rotation of a contact that is interacting with the device (e.g., in one or more of the methods described below, instead of using a fingerprint sensor to detect rotation of a fingerprint/contact, the set of one or more orientation sensors is used to detect rotation of the contact that includes the fingerprint, with or without detecting features of the fingerprint). 
     In some embodiments, features of fingerprints and comparisons between features of detected fingerprints and features of stored fingerprints are performed by secured dedicated computing hardware (e.g., one or more processors, memory and/or communications busses) that are separate from processor(s)  120 , so as to improve security of the fingerprint data generated, stored and processed by the one or more fingerprint sensors. In some embodiments, features of fingerprints and comparisons between features of detected fingerprints and features of enrolled fingerprints are performed by processor(s)  120  using a fingerprint analysis module. 
     In some embodiments, during an enrollment process, the device (e.g., a fingerprint analysis module or a separate secure module in communication with the one or more fingerprint sensors) collects biometric information about one or more fingerprints of the user (e.g., identifying relative location of a plurality of minutia points in a fingerprint of the user). After the enrollment process has been completed the biometric information is stored at the device (e.g., in a secure fingerprint module) for later use in authenticating detected fingerprints. In some embodiments, the biometric information that is stored at the device excludes images of the fingerprints and also excludes information from which images of the fingerprints could be reconstructed so that images of the fingerprints are not inadvertently made available if the security of the device is compromised. In some embodiments, during an authentication process, the device (e.g., a fingerprint analysis module or a separate secure module in communication with the one or more fingerprint sensors) determines whether a finger input detected by the one or more fingerprint sensors includes a fingerprint that matches a previously enrolled fingerprint by collecting biometric information about a fingerprint detected on the one or more fingerprint sensors (e.g., identifying relative locations of a plurality of minutia points in the fingerprint detected on the one or more fingerprint sensors) and comparing the biometric information that corresponds to the detected fingerprint to biometric information that corresponds to the enrolled fingerprints(s). In some embodiments, comparing the biometric information that corresponds to the detected fingerprint to biometric information that corresponds to the enrolled fingerprints(s) includes comparing a type and location of minutia points in the biometric information that corresponds to the detected fingerprint to a type and location of minutia points in the biometric information that corresponds to the enrolled fingerprints. However the determination as to whether or not a finger input includes a fingerprint that matches a previously enrolled fingerprint that is enrolled with the device is, optionally, performed using any of a number of well known fingerprint authentication techniques for determining whether a detected fingerprint matches an enrolled fingerprint. 
     Device  100  optionally also includes one or more depth camera sensors  175 .  FIG. 1A  shows a depth camera sensor coupled to depth camera controller  169  in I/O subsystem  106 . Depth camera sensor  175  receives data from the environment, projected through a sensor. In conjunction with imaging module  143  (also called a camera module), depth camera sensor  175  camera is optionally used to determine a depth map of different portions of an image captured by the imaging module  143 . In some embodiments, a depth camera sensor is located on the front of device  100  so that the user&#39;s image with depth information is available for use by different functions of the device such as video conferencing capturing selfies with depth map data, and authenticating a user of the device. In some embodiments, the position of depth camera sensors  175  can be changed by the user (e.g., by rotating the lens and the sensor in the device housing) so that a depth camera sensors  175  is used along with the touch screen display for both video conferencing and still and/or video image acquisition. 
     In some embodiments, the software components stored in memory  102  include operating system  126 , communication module (or set of instructions)  128 , contact/motion module (or set of instructions)  130 , graphics module (or set of instructions)  132 , text input module (or set of instructions)  134 , Global Positioning System (GPS) module (or set of instructions)  135 , and applications (or sets of instructions)  136 . Furthermore, in some embodiments, memory  102  ( FIG. 1A ) or  370  ( FIG. 3 ) stores device/global internal state  157 , as shown in  FIGS. 1A and 3 . Device/global internal state  157  includes one or more of: active application state, indicating which applications, if any, are currently active; display state, indicating what applications, views or other information occupy various regions of touch screen display  112 ; sensor state, including information obtained from the device&#39;s various sensors and input control devices  116 ; and location information concerning the device&#39;s location and/or attitude. 
     Operating system  126  (e.g., Darwin, RTXC, LINUX, UNIX, OS X, iOS, WINDOWS, or an embedded operating system such as VxWorks) includes various software components and/or drivers for controlling and managing general system tasks (e.g., memory management, storage device control, power management, etc.) and facilitates communication between various hardware and software components. 
     Communication module  128  facilitates communication with other devices over one or more external ports  124  and also includes various software components for handling data received by RF circuitry  108  and/or external port  124 . External port  124  (e.g., Universal Serial Bus (USB), FIREWIRE, etc.) is adapted for coupling directly to other devices or indirectly over a network (e.g., the Internet, wireless LAN, etc.). In some embodiments, the external port is a multi-pin (e.g., 30-pin) connector that is the same as, or similar to and/or compatible with, the 30-pin connector used on iPod® (trademark of Apple Inc.) devices. 
     Contact/motion module  130  optionally detects contact with touch screen  112  (in conjunction with display controller  156 ) and other touch-sensitive devices (e.g., a touchpad or physical click wheel). Contact/motion module  130  includes various software components for performing various operations related to detection of contact, such as determining if contact has occurred (e.g., detecting a finger-down event), determining an intensity of the contact (e.g., the force or pressure of the contact or a substitute for the force or pressure of the contact), determining if there is movement of the contact and tracking the movement across the touch-sensitive surface (e.g., detecting one or more finger-dragging events), and determining if the contact has ceased (e.g., detecting a finger-up event or a break in contact). Contact/motion module  130  receives contact data from the touch-sensitive surface. Determining movement of the point of contact, which is represented by a series of contact data, optionally includes determining speed (magnitude), velocity (magnitude and direction), and/or an acceleration (a change in magnitude and/or direction) of the point of contact. These operations are, optionally, applied to single contacts (e.g., one finger contacts) or to multiple simultaneous contacts (e.g., “multitouch”/multiple finger contacts). In some embodiments, contact/motion module  130  and display controller  156  detect contact on a touchpad. 
     In some embodiments, contact/motion module  130  uses a set of one or more intensity thresholds to determine whether an operation has been performed by a user (e.g., to determine whether a user has “clicked” on an icon). In some embodiments, at least a subset of the intensity thresholds are determined in accordance with software parameters (e.g., the intensity thresholds are not determined by the activation thresholds of particular physical actuators and can be adjusted without changing the physical hardware of device  100 ). For example, a mouse “click” threshold of a trackpad or touch screen display can be set to any of a large range of predefined threshold values without changing the trackpad or touch screen display hardware. Additionally, in some implementations, a user of the device is provided with software settings for adjusting one or more of the set of intensity thresholds (e.g., by adjusting individual intensity thresholds and/or by adjusting a plurality of intensity thresholds at once with a system-level click “intensity” parameter). 
     Contact/motion module  130  optionally detects a gesture input by a user. Different gestures on the touch-sensitive surface have different contact patterns (e.g., different motions, timings, and/or intensities of detected contacts). Thus, a gesture is, optionally, detected by detecting a particular contact pattern. For example, detecting a finger tap gesture includes detecting a finger-down event followed by detecting a finger-up (liftoff) event at the same position (or substantially the same position) as the finger-down event (e.g., at the position of an icon). As another example, detecting a finger swipe gesture on the touch-sensitive surface includes detecting a finger-down event followed by detecting one or more finger-dragging events, and subsequently followed by detecting a finger-up (liftoff) event. 
     Graphics module  132  includes various known software components for rendering and displaying graphics on touch screen  112  or other display, including components for changing the visual impact (e.g., brightness, transparency, saturation, contrast, or other visual property) of graphics that are displayed. As used herein, the term “graphics” includes any object that can be displayed to a user, including, without limitation, text, web pages, icons (such as user-interface objects including soft keys), digital images, videos, animations, and the like. 
     In some embodiments, graphics module  132  stores data representing graphics to be used. Each graphic is, optionally, assigned a corresponding code. Graphics module  132  receives, from applications etc., one or more codes specifying graphics to be displayed along with, if necessary, coordinate data and other graphic property data, and then generates screen image data to output to display controller  156 . 
     Haptic feedback module  133  includes various software components for generating instructions used by tactile output generator(s)  167  to produce tactile outputs at one or more locations on device  100  in response to user interactions with device  100 . 
     Text input module  134 , which is, optionally, a component of graphics module  132 , provides soft keyboards for entering text in various applications (e.g., contacts  137 , e-mail  140 , IM  141 , browser  147 , and any other application that needs text input). 
     GPS module  135  determines the location of the device and provides this information for use in various applications (e.g., to telephone  138  for use in location-based dialing; to camera  143  as picture/video metadata; and to applications that provide location-based services such as weather widgets, local yellow page widgets, and map/navigation widgets). 
     Applications  136  optionally include the following modules (or sets of instructions), or a subset or superset thereof:
         Contacts module  137  (sometimes called an address book or contact list);   Telephone module  138 ;   Video conference module  139 ;   E-mail client module  140 ;   Instant messaging (IM) module  141 ;   Workout support module  142 ;   Camera module  143  for still and/or video images;   Image management module  144 ;   Video player module;   Music player module;   Browser module  147 ;   Calendar module  148 ;   Widget modules  149 , which optionally include one or more of: weather widget  149 - 1 , stocks widget  149 - 2 , calculator widget  149 - 3 , alarm clock widget  149 - 4 , dictionary widget  149 - 5 , and other widgets obtained by the user, as well as user-created widgets  149 - 6 ;   Widget creator module  150  for making user-created widgets  149 - 6 ;   Search module  151 ;   Video and music player module  152 , which merges video player module and music player module;   Notes module  153 ;   Map module  154 ; and/or   Online video module  155 .       

     Examples of other applications  136  that are, optionally, stored in memory  102  include other word processing applications, other image editing applications, drawing applications, presentation applications, JAVA-enabled applications, encryption, digital rights management, voice recognition, and voice replication. 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , contacts module  137  are, optionally, used to manage an address book or contact list (e.g., stored in application internal state  192  of contacts module  137  in memory  102  or memory  370 ), including: adding name(s) to the address book; deleting name(s) from the address book; associating telephone number(s), e-mail address(es), physical address(es) or other information with a name; associating an image with a name; categorizing and sorting names; providing telephone numbers or e-mail addresses to initiate and/or facilitate communications by telephone  138 , video conference module  139 , e-mail  140 , or IM  141 ; and so forth. 
     In conjunction with RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , telephone module  138  are optionally, used to enter a sequence of characters corresponding to a telephone number, access one or more telephone numbers in contacts module  137 , modify a telephone number that has been entered, dial a respective telephone number, conduct a conversation, and disconnect or hang up when the conversation is completed. As noted above, the wireless communication optionally uses any of a plurality of communications standards, protocols, and technologies. 
     In conjunction with RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , touch screen  112 , display controller  156 , optical sensor  164 , optical sensor controller  158 , contact/motion module  130 , graphics module  132 , text input module  134 , contacts module  137 , and telephone module  138 , video conference module  139  includes executable instructions to initiate, conduct, and terminate a video conference between a user and one or more other participants in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , e-mail client module  140  includes executable instructions to create, send, receive, and manage e-mail in response to user instructions. In conjunction with image management module  144 , e-mail client module  140  makes it very easy to create and send e-mails with still or video images taken with camera module  143 . 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , the instant messaging module  141  includes executable instructions to enter a sequence of characters corresponding to an instant message, to modify previously entered characters, to transmit a respective instant message (for example, using a Short Message Service (SMS) or Multimedia Message Service (MMS) protocol for telephony-based instant messages or using XMPP, SIMPLE, or IMPS for Internet-based instant messages), to receive instant messages, and to view received instant messages. In some embodiments, transmitted and/or received instant messages optionally include graphics, photos, audio files, video files and/or other attachments as are supported in an MMS and/or an Enhanced Messaging Service (EMS). As used herein, “instant messaging” refers to both telephony-based messages (e.g., messages sent using SMS or MMS) and Internet-based messages (e.g., messages sent using XIVIPP, SIMPLE, or IMPS). 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , GPS module  135 , map module  154 , and music player module, workout support module  142  includes executable instructions to create workouts (e.g., with time, distance, and/or calorie burning goals); communicate with workout sensors (sports devices); receive workout sensor data; calibrate sensors used to monitor a workout; select and play music for a workout; and display, store, and transmit workout data. 
     In conjunction with touch screen  112 , display controller  156 , optical sensor(s)  164 , optical sensor controller  158 , contact/motion module  130 , graphics module  132 , and image management module  144 , camera module  143  includes executable instructions to capture still images or video (including a video stream) and store them into memory  102 , modify characteristics of a still image or video, or delete a still image or video from memory  102 . 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , and camera module  143 , image management module  144  includes executable instructions to arrange, modify (e.g., edit), or otherwise manipulate, label, delete, present (e.g., in a digital slide show or album), and store still and/or video images. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , browser module  147  includes executable instructions to browse the Internet in accordance with user instructions, including searching, linking to, receiving, and displaying web pages or portions thereof, as well as attachments and other files linked to web pages. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , e-mail client module  140 , and browser module  147 , calendar module  148  includes executable instructions to create, display, modify, and store calendars and data associated with calendars (e.g., calendar entries, to-do lists, etc.) in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , and browser module  147 , widget modules  149  are mini-applications that are, optionally, downloaded and used by a user (e.g., weather widget  149 - 1 , stocks widget  149 - 2 , calculator widget  149 - 3 , alarm clock widget  149 - 4 , and dictionary widget  149 - 5 ) or created by the user (e.g., user-created widget  149 - 6 ). In some embodiments, a widget includes an HTML (Hypertext Markup Language) file, a CSS (Cascading Style Sheets) file, and a JavaScript file. In some embodiments, a widget includes an XML (Extensible Markup Language) file and a JavaScript file (e.g., Yahoo! Widgets). 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , and browser module  147 , the widget creator module  150  are, optionally, used by a user to create widgets (e.g., turning a user-specified portion of a web page into a widget). 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , search module  151  includes executable instructions to search for text, music, sound, image, video, and/or other files in memory  102  that match one or more search criteria (e.g., one or more user-specified search terms) in accordance with user instructions. 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , audio circuitry  110 , speaker  111 , RF circuitry  108 , and browser module  147 , video and music player module  152  includes executable instructions that allow the user to download and play back recorded music and other sound files stored in one or more file formats, such as MP3 or AAC files, and executable instructions to display, present, or otherwise play back videos (e.g., on touch screen  112  or on an external, connected display via external port  124 ). In some embodiments, device  100  optionally includes the functionality of an MP3 player, such as an iPod (trademark of Apple Inc.). 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , notes module  153  includes executable instructions to create and manage notes, to-do lists, and the like in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , GPS module  135 , and browser module  147 , map module  154  are, optionally, used to receive, display, modify, and store maps and data associated with maps (e.g., driving directions, data on stores and other points of interest at or near a particular location, and other location-based data) in accordance with user instructions. 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , audio circuitry  110 , speaker  111 , RF circuitry  108 , text input module  134 , e-mail client module  140 , and browser module  147 , online video module  155  includes instructions that allow the user to access, browse, receive (e.g., by streaming and/or download), play back (e.g., on the touch screen or on an external, connected display via external port  124 ), send an e-mail with a link to a particular online video, and otherwise manage online videos in one or more file formats, such as H.264. In some embodiments, instant messaging module  141 , rather than e-mail client module  140 , is used to send a link to a particular online video. Additional description of the online video application can be found in U.S. Provisional Patent Application No. 60/936,562, “Portable Multifunction Device, Method, and Graphical User Interface for Playing Online Videos,” filed Jun. 20, 2007, and U.S. patent application Ser. No. 11/968,067, “Portable Multifunction Device, Method, and Graphical User Interface for Playing Online Videos,” filed Dec. 31, 2007, the contents of which are hereby incorporated by reference in their entirety. 
     Each of the above-identified modules and applications corresponds to a set of executable instructions for performing one or more functions described above and the methods described in this application (e.g., the computer-implemented methods and other information processing methods described herein). These modules (e.g., sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules are, optionally, combined or otherwise rearranged in various embodiments. For example, video player module is, optionally, combined with music player module into a single module (e.g., video and music player module  152 ,  FIG. 1A ). In some embodiments, memory  102  optionally stores a subset of the modules and data structures identified above. Furthermore, memory  102  optionally stores additional modules and data structures not described above. 
     In some embodiments, device  100  is a device where operation of a predefined set of functions on the device is performed exclusively through a touch screen and/or a touchpad. By using a touch screen and/or a touchpad as the primary input control device for operation of device  100 , the number of physical input control devices (such as push buttons, dials, and the like) on device  100  is, optionally, reduced. 
     The predefined set of functions that are performed exclusively through a touch screen and/or a touchpad optionally include navigation between user interfaces. In some embodiments, the touchpad, when touched by the user, navigates device  100  to a main, home, or root menu from any user interface that is displayed on device  100 . In such embodiments, a “menu button” is implemented using a touchpad. In some other embodiments, the menu button is a physical push button or other physical input control device instead of a touchpad. 
       FIG. 1B  is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. In some embodiments, memory  102  ( FIG. 1A ) or  370  ( FIG. 3 ) includes event sorter  170  (e.g., in operating system  126 ) and a respective application  136 - 1  (e.g., any of the aforementioned applications  137 - 151 ,  155 ,  380 - 390 ). 
     Event sorter  170  receives event information and determines the application  136 - 1  and application view  191  of application  136 - 1  to which to deliver the event information. Event sorter  170  includes event monitor  171  and event dispatcher module  174 . In some embodiments, application  136 - 1  includes application internal state  192 , which indicates the current application view(s) displayed on touch-sensitive display  112  when the application is active or executing. In some embodiments, device/global internal state  157  is used by event sorter  170  to determine which application(s) is (are) currently active, and application internal state  192  is used by event sorter  170  to determine application views  191  to which to deliver event information. 
     In some embodiments, application internal state  192  includes additional information, such as one or more of: resume information to be used when application  136 - 1  resumes execution, user interface state information that indicates information being displayed or that is ready for display by application  136 - 1 , a state queue for enabling the user to go back to a prior state or view of application  136 - 1 , and a redo/undo queue of previous actions taken by the user. 
     Event monitor  171  receives event information from peripherals interface  118 . Event information includes information about a sub-event (e.g., a user touch on touch-sensitive display  112 , as part of a multi-touch gesture). Peripherals interface  118  transmits information it receives from I/O subsystem  106  or a sensor, such as proximity sensor  166 , accelerometer(s)  168 , and/or microphone  113  (through audio circuitry  110 ). Information that peripherals interface  118  receives from I/O subsystem  106  includes information from touch-sensitive display  112  or a touch-sensitive surface. 
     In some embodiments, event monitor  171  sends requests to the peripherals interface  118  at predetermined intervals. In response, peripherals interface  118  transmits event information. In other embodiments, peripherals interface  118  transmits event information only when there is a significant event (e.g., receiving an input above a predetermined noise threshold and/or for more than a predetermined duration). 
     In some embodiments, event sorter  170  also includes a hit view determination module  172  and/or an active event recognizer determination module  173 . 
     Hit view determination module  172  provides software procedures for determining where a sub-event has taken place within one or more views when touch-sensitive display  112  displays more than one view. Views are made up of controls and other elements that a user can see on the display. 
     Another aspect of the user interface associated with an application is a set of views, sometimes herein called application views or user interface windows, in which information is displayed and touch-based gestures occur. The application views (of a respective application) in which a touch is detected optionally correspond to programmatic levels within a programmatic or view hierarchy of the application. For example, the lowest level view in which a touch is detected is, optionally, called the hit view, and the set of events that are recognized as proper inputs are, optionally, determined based, at least in part, on the hit view of the initial touch that begins a touch-based gesture. 
     Hit view determination module  172  receives information related to sub-events of a touch-based gesture. When an application has multiple views organized in a hierarchy, hit view determination module  172  identifies a hit view as the lowest view in the hierarchy which should handle the sub-event. In most circumstances, the hit view is the lowest level view in which an initiating sub-event occurs (e.g., the first sub-event in the sequence of sub-events that form an event or potential event). Once the hit view is identified by the hit view determination module  172 , the hit view typically receives all sub-events related to the same touch or input source for which it was identified as the hit view. 
     Active event recognizer determination module  173  determines which view or views within a view hierarchy should receive a particular sequence of sub-events. In some embodiments, active event recognizer determination module  173  determines that only the hit view should receive a particular sequence of sub-events. In other embodiments, active event recognizer determination module  173  determines that all views that include the physical location of a sub-event are actively involved views, and therefore determines that all actively involved views should receive a particular sequence of sub-events. In other embodiments, even if touch sub-events were entirely confined to the area associated with one particular view, views higher in the hierarchy would still remain as actively involved views. 
     Event dispatcher module  174  dispatches the event information to an event recognizer (e.g., event recognizer  180 ). In embodiments including active event recognizer determination module  173 , event dispatcher module  174  delivers the event information to an event recognizer determined by active event recognizer determination module  173 . In some embodiments, event dispatcher module  174  stores in an event queue the event information, which is retrieved by a respective event receiver  182 . 
     In some embodiments, operating system  126  includes event sorter  170 . Alternatively, application  136 - 1  includes event sorter  170 . In yet other embodiments, event sorter  170  is a stand-alone module, or a part of another module stored in memory  102 , such as contact/motion module  130 . 
     In some embodiments, application  136 - 1  includes a plurality of event handlers  190  and one or more application views  191 , each of which includes instructions for handling touch events that occur within a respective view of the application&#39;s user interface. Each application view  191  of the application  136 - 1  includes one or more event recognizers  180 . Typically, a respective application view  191  includes a plurality of event recognizers  180 . In other embodiments, one or more of event recognizers  180  are part of a separate module, such as a user interface kit (not shown) or a higher level object from which application  136 - 1  inherits methods and other properties. In some embodiments, a respective event handler  190  includes one or more of: data updater  176 , object updater  177 , GUI updater  178 , and/or event data  179  received from event sorter  170 . Event handler  190  optionally utilizes or calls data updater  176 , object updater  177 , or GUI updater  178  to update the application internal state  192 . Alternatively, one or more of the application views  191  include one or more respective event handlers  190 . Also, in some embodiments, one or more of data updater  176 , object updater  177 , and GUI updater  178  are included in a respective application view  191 . 
     A respective event recognizer  180  receives event information (e.g., event data  179 ) from event sorter  170  and identifies an event from the event information. Event recognizer  180  includes event receiver  182  and event comparator  184 . In some embodiments, event recognizer  180  also includes at least a subset of: metadata  183 , and event delivery instructions  188  (which optionally include sub-event delivery instructions). 
     Event receiver  182  receives event information from event sorter  170 . The event information includes information about a sub-event, for example, a touch or a touch movement. Depending on the sub-event, the event information also includes additional information, such as location of the sub-event. When the sub-event concerns motion of a touch, the event information optionally also includes speed and direction of the sub-event. In some embodiments, events include rotation of the device from one orientation to another (e.g., from a portrait orientation to a landscape orientation, or vice versa), and the event information includes corresponding information about the current orientation (also called device attitude) of the device. 
     Event comparator  184  compares the event information to predefined event or sub-event definitions and, based on the comparison, determines an event or sub-event, or determines or updates the state of an event or sub-event. In some embodiments, event comparator  184  includes event definitions  186 . Event definitions  186  contain definitions of events (e.g., predefined sequences of sub-events), for example, event  1  ( 187 - 1 ), event  2  ( 187 - 2 ), and others. In some embodiments, sub-events in an event ( 187 ) include, for example, touch begin, touch end, touch movement, touch cancellation, and multiple touching. In one example, the definition for event  1  ( 187 - 1 ) is a double tap on a displayed object. The double tap, for example, comprises a first touch (touch begin) on the displayed object for a predetermined phase, a first liftoff (touch end) for a predetermined phase, a second touch (touch begin) on the displayed object for a predetermined phase, and a second liftoff (touch end) for a predetermined phase. In another example, the definition for event  2  ( 187 - 2 ) is a dragging on a displayed object. The dragging, for example, comprises a touch (or contact) on the displayed object for a predetermined phase, a movement of the touch across touch-sensitive display  112 , and liftoff of the touch (touch end). In some embodiments, the event also includes information for one or more associated event handlers  190 . 
     In some embodiments, event definition  187  includes a definition of an event for a respective user-interface object. In some embodiments, event comparator  184  performs a hit test to determine which user-interface object is associated with a sub-event. For example, in an application view in which three user-interface objects are displayed on touch-sensitive display  112 , when a touch is detected on touch-sensitive display  112 , event comparator  184  performs a hit test to determine which of the three user-interface objects is associated with the touch (sub-event). If each displayed object is associated with a respective event handler  190 , the event comparator uses the result of the hit test to determine which event handler  190  should be activated. For example, event comparator  184  selects an event handler associated with the sub-event and the object triggering the hit test. 
     In some embodiments, the definition for a respective event ( 187 ) also includes delayed actions that delay delivery of the event information until after it has been determined whether the sequence of sub-events does or does not correspond to the event recognizer&#39;s event type. 
     When a respective event recognizer  180  determines that the series of sub-events do not match any of the events in event definitions  186 , the respective event recognizer  180  enters an event impossible, event failed, or event ended state, after which it disregards subsequent sub-events of the touch-based gesture. In this situation, other event recognizers, if any, that remain active for the hit view continue to track and process sub-events of an ongoing touch-based gesture. 
     In some embodiments, a respective event recognizer  180  includes metadata  183  with configurable properties, flags, and/or lists that indicate how the event delivery system should perform sub-event delivery to actively involved event recognizers. In some embodiments, metadata  183  includes configurable properties, flags, and/or lists that indicate how event recognizers interact, or are enabled to interact, with one another. In some embodiments, metadata  183  includes configurable properties, flags, and/or lists that indicate whether sub-events are delivered to varying levels in the view or programmatic hierarchy. 
     In some embodiments, a respective event recognizer  180  activates event handler  190  associated with an event when one or more particular sub-events of an event are recognized. In some embodiments, a respective event recognizer  180  delivers event information associated with the event to event handler  190 . Activating an event handler  190  is distinct from sending (and deferred sending) sub-events to a respective hit view. In some embodiments, event recognizer  180  throws a flag associated with the recognized event, and event handler  190  associated with the flag catches the flag and performs a predefined process. 
     In some embodiments, event delivery instructions  188  include sub-event delivery instructions that deliver event information about a sub-event without activating an event handler. Instead, the sub-event delivery instructions deliver event information to event handlers associated with the series of sub-events or to actively involved views. Event handlers associated with the series of sub-events or with actively involved views receive the event information and perform a predetermined process. 
     In some embodiments, data updater  176  creates and updates data used in application  136 - 1 . For example, data updater  176  updates the telephone number used in contacts module  137 , or stores a video file used in video player module. In some embodiments, object updater  177  creates and updates objects used in application  136 - 1 . For example, object updater  177  creates a new user-interface object or updates the position of a user-interface object. GUI updater  178  updates the GUI. For example, GUI updater  178  prepares display information and sends it to graphics module  132  for display on a touch-sensitive display. 
     In some embodiments, event handler(s)  190  includes or has access to data updater  176 , object updater  177 , and GUI updater  178 . In some embodiments, data updater  176 , object updater  177 , and GUI updater  178  are included in a single module of a respective application  136 - 1  or application view  191 . In other embodiments, they are included in two or more software modules. 
       FIG. 1C  is a block diagram illustrating a tactile output module in accordance with some embodiments. In some embodiments, I/O subsystem  106  (e.g., haptic feedback controller  161  ( FIG. 1A ) and/or other input controller(s)  160  ( FIG. 1A )) includes at least some of the example components shown in  FIG. 1C . In some embodiments, peripherals interface  118  includes at least some of the example components shown in  FIG. 1C . 
     In some embodiments, the tactile output module includes haptic feedback module  133 . In some embodiments, haptic feedback module  133  aggregates and combines tactile outputs for user interface feedback from software applications on the electronic device (e.g., feedback that is responsive to user inputs that correspond to displayed user interfaces and alerts and other notifications that indicate the performance of operations or occurrence of events in user interfaces of the electronic device). Haptic feedback module  133  includes one or more of: waveform module  123  (for providing waveforms used for generating tactile outputs), mixer  125  (for mixing waveforms, such as waveforms in different channels), compressor  127  (for reducing or compressing a dynamic range of the waveforms), low-pass filter  129  (for filtering out high frequency signal components in the waveforms), and thermal controller  131  (for adjusting the waveforms in accordance with thermal conditions). In some embodiments, haptic feedback module  133  is included in haptic feedback controller  161  ( FIG. 1A ). In some embodiments, a separate unit of haptic feedback module  133  (or a separate implementation of haptic feedback module  133 ) is also included in an audio controller (e.g., audio circuitry  110 ,  FIG. 1A ) and used for generating audio signals. In some embodiments, a single haptic feedback module  133  is used for generating audio signals and generating waveforms for tactile outputs. 
     In some embodiments, haptic feedback module  133  also includes trigger module  121  (e.g., a software application, operating system, or other software module that determines a tactile output is to be generated and initiates the process for generating the corresponding tactile output). In some embodiments, trigger module  121  generates trigger signals for initiating generation of waveforms (e.g., by waveform module  123 ). For example, trigger module  121  generates trigger signals based on preset timing criteria. In some embodiments, trigger module  121  receives trigger signals from outside haptic feedback module  133  (e.g., in some embodiments, haptic feedback module  133  receives trigger signals from hardware input processing module  146  located outside haptic feedback module  133 ) and relays the trigger signals to other components within haptic feedback module  133  (e.g., waveform module  123 ) or software applications that trigger operations (e.g., with trigger module  121 ) based on activation of a user interface element (e.g., an application icon or an affordance within an application) or a hardware input device (e.g., a home button or an intensity-sensitive input surface, such as an intensity-sensitive touch screen). In some embodiments, trigger module  121  also receives tactile feedback generation instructions (e.g., from haptic feedback module  133 ,  FIGS. 1A and 3 ). In some embodiments, trigger module  121  generates trigger signals in response to haptic feedback module  133  (or trigger module  121  in haptic feedback module  133 ) receiving tactile feedback instructions (e.g., from haptic feedback module  133 ,  FIGS. 1A and 3 ). 
     Waveform module  123  receives trigger signals (e.g., from trigger module  121 ) as an input, and in response to receiving trigger signals, provides waveforms for generation of one or more tactile outputs (e.g., waveforms selected from a predefined set of waveforms designated for use by waveform module  123 , such as the waveforms described in greater detail below with reference to  FIGS. 4C-4D ). 
     Mixer  125  receives waveforms (e.g., from waveform module  123 ) as an input, and mixes together the waveforms. For example, when mixer  125  receives two or more waveforms (e.g., a first waveform in a first channel and a second waveform that at least partially overlaps with the first waveform in a second channel) mixer  125  outputs a combined waveform that corresponds to a sum of the two or more waveforms. In some embodiments, mixer  125  also modifies one or more waveforms of the two or more waveforms to emphasize particular waveform(s) over the rest of the two or more waveforms (e.g., by increasing a scale of the particular waveform(s) and/or decreasing a scale of the rest of the waveforms). In some circumstances, mixer  125  selects one or more waveforms to remove from the combined waveform (e.g., the waveform from the oldest source is dropped when there are waveforms from more than three sources that have been requested to be output concurrently by tactile output generator  167 ). 
     Compressor  127  receives waveforms (e.g., a combined waveform from mixer  125 ) as an input, and modifies the waveforms. In some embodiments, compressor  127  reduces the waveforms (e.g., in accordance with physical specifications of tactile output generators  167  ( FIG. 1A ) or  357  ( FIG. 3 )) so that tactile outputs corresponding to the waveforms are reduced. In some embodiments, compressor  127  limits the waveforms, such as by enforcing a predefined maximum amplitude for the waveforms. For example, compressor  127  reduces amplitudes of portions of waveforms that exceed a predefined amplitude threshold while maintaining amplitudes of portions of waveforms that do not exceed the predefined amplitude threshold. In some embodiments, compressor  127  reduces a dynamic range of the waveforms. In some embodiments, compressor  127  dynamically reduces the dynamic range of the waveforms so that the combined waveforms remain within performance specifications of the tactile output generator  167  (e.g., force and/or moveable mass displacement limits). 
     Low-pass filter  129  receives waveforms (e.g., compressed waveforms from compressor  127 ) as an input, and filters (e.g., smooths) the waveforms (e.g., removes or reduces high frequency signal components in the waveforms). For example, in some instances, compressor  127  includes, in compressed waveforms, extraneous signals (e.g., high frequency signal components) that interfere with the generation of tactile outputs and/or exceed performance specifications of tactile output generator  167  when the tactile outputs are generated in accordance with the compressed waveforms. Low-pass filter  129  reduces or removes such extraneous signals in the waveforms. 
     Thermal controller  131  receives waveforms (e.g., filtered waveforms from low-pass filter  129 ) as an input, and adjusts the waveforms in accordance with thermal conditions of device  100  (e.g., based on internal temperatures detected within device  100 , such as the temperature of haptic feedback controller  161 , and/or external temperatures detected by device  100 ). For example, in some cases, the output of haptic feedback controller  161  varies depending on the temperature (e.g. haptic feedback controller  161 , in response to receiving same waveforms, generates a first tactile output when haptic feedback controller  161  is at a first temperature and generates a second tactile output when haptic feedback controller  161  is at a second temperature that is distinct from the first temperature). For example, the magnitude (or the amplitude) of the tactile outputs can vary depending on the temperature. To reduce the effect of the temperature variations, the waveforms are modified (e.g., an amplitude of the waveforms is increased or decreased based on the temperature). 
     In some embodiments, haptic feedback module  133  (e.g., trigger module  121 ) is coupled to hardware input processing module  146 . In some embodiments, other input controller(s)  160  in  FIG. 1A  includes hardware input processing module  146 . In some embodiments, hardware input processing module  146  receives inputs from hardware input device  145  (e.g., other input or control devices  116  in  FIG. 1A , such as a home button or an intensity-sensitive input surface, such as an intensity-sensitive touch screen). In some embodiments, hardware input device  145  is any input device described herein, such as touch-sensitive display system  112  ( FIG. 1A ), keyboard/mouse  350  ( FIG. 3 ), touchpad  355  ( FIG. 3 ), one of other input or control devices  116  ( FIG. 1A ), or an intensity-sensitive home button. In some embodiments, hardware input device  145  consists of an intensity-sensitive home button, and not touch-sensitive display system  112  ( FIG. 1A ), keyboard/mouse  350  ( FIG. 3 ), or touchpad  355  ( FIG. 3 ). In some embodiments, in response to inputs from hardware input device  145  (e.g., an intensity-sensitive home button or a touch screen), hardware input processing module  146  provides one or more trigger signals to haptic feedback module  133  to indicate that a user input satisfying predefined input criteria, such as an input corresponding to a “click” of a home button (e.g., a “down click” or an “up click”), has been detected. In some embodiments, haptic feedback module  133  provides waveforms that correspond to the “click” of a home button in response to the input corresponding to the “click” of a home button, simulating a haptic feedback of pressing a physical home button. 
     In some embodiments, the tactile output module includes haptic feedback controller  161  (e.g., haptic feedback controller  161  in  FIG. 1A ), which controls the generation of tactile outputs. In some embodiments, haptic feedback controller  161  is coupled to a plurality of tactile output generators, and selects one or more tactile output generators of the plurality of tactile output generators and sends waveforms to the selected one or more tactile output generators for generating tactile outputs. In some embodiments, haptic feedback controller  161  coordinates tactile output requests that correspond to activation of hardware input device  145  and tactile output requests that correspond to software events (e.g., tactile output requests from haptic feedback module  133 ) and modifies one or more waveforms of the two or more waveforms to emphasize particular waveform(s) over the rest of the two or more waveforms (e.g., by increasing a scale of the particular waveform(s) and/or decreasing a scale of the rest of the waveforms, such as to prioritize tactile outputs that correspond to activations of hardware input device  145  over tactile outputs that correspond to software events). 
     In some embodiments, as shown in  FIG. 1C , an output of haptic feedback controller  161  is coupled to audio circuitry of device  100  (e.g., audio circuitry  110 ,  FIG. 1A ), and provides audio signals to audio circuitry of device  100 . In some embodiments, haptic feedback controller  161  provides both waveforms used for generating tactile outputs and audio signals used for providing audio outputs in conjunction with generation of the tactile outputs. In some embodiments, haptic feedback controller  161  modifies audio signals and/or waveforms (used for generating tactile outputs) so that the audio outputs and the tactile outputs are synchronized (e.g., by delaying the audio signals and/or waveforms). In some embodiments, haptic feedback controller  161  includes a digital-to-analog converter used for converting digital waveforms into analog signals, which are received by amplifier  163  and/or tactile output generator  167 . 
     In some embodiments, the tactile output module includes amplifier  163 . In some embodiments, amplifier  163  receives waveforms (e.g., from haptic feedback controller  161 ) and amplifies the waveforms prior to sending the amplified waveforms to tactile output generator  167  (e.g., any of tactile output generators  167  ( FIG. 1A ) or  357  ( FIG. 3 )). For example, amplifier  163  amplifies the received waveforms to signal levels that are in accordance with physical specifications of tactile output generator  167  (e.g., to a voltage and/or a current required by tactile output generator  167  for generating tactile outputs so that the signals sent to tactile output generator  167  produce tactile outputs that correspond to the waveforms received from haptic feedback controller  161 ) and sends the amplified waveforms to tactile output generator  167 . In response, tactile output generator  167  generates tactile outputs (e.g., by shifting a moveable mass back and forth in one or more dimensions relative to a neutral position of the moveable mass). 
     In some embodiments, the tactile output module includes sensor  169 , which is coupled to tactile output generator  167 . Sensor  169  detects states or state changes (e.g., mechanical position, physical displacement, and/or movement) of tactile output generator  167  or one or more components of tactile output generator  167  (e.g., one or more moving parts, such as a membrane, used to generate tactile outputs). In some embodiments, sensor  169  is a magnetic field sensor (e.g., a Hall effect sensor) or other displacement and/or movement sensor. In some embodiments, sensor  169  provides information (e.g., a position, a displacement, and/or a movement of one or more parts in tactile output generator  167 ) to haptic feedback controller  161  and, in accordance with the information provided by sensor  169  about the state of tactile output generator  167 , haptic feedback controller  161  adjusts the waveforms output from haptic feedback controller  161  (e.g., waveforms sent to tactile output generator  167 , optionally via amplifier  163 ). 
     It shall be understood that the foregoing discussion regarding event handling of user touches on touch-sensitive displays also applies to other forms of user inputs to operate multifunction devices  100  with input devices, not all of which are initiated on touch screens. For example, mouse movement and mouse button presses, optionally coordinated with single or multiple keyboard presses or holds; contact movements such as taps, drags, scrolls, etc. on touchpads; pen stylus inputs; movement of the device; oral instructions; detected eye movements; biometric inputs; and/or any combination thereof are optionally utilized as inputs corresponding to sub-events which define an event to be recognized. 
       FIG. 2  illustrates a portable multifunction device  100  having a touch screen  112  in accordance with some embodiments. The touch screen optionally displays one or more graphics within user interface (UI)  200 . In this embodiment, as well as others described below, a user is enabled to select one or more of the graphics by making a gesture on the graphics, for example, with one or more fingers  202  (not drawn to scale in the figure) or one or more styluses  203  (not drawn to scale in the figure). In some embodiments, selection of one or more graphics occurs when the user breaks contact with the one or more graphics. In some embodiments, the gesture optionally includes one or more taps, one or more swipes (from left to right, right to left, upward and/or downward), and/or a rolling of a finger (from right to left, left to right, upward and/or downward) that has made contact with device  100 . In some implementations or circumstances, inadvertent contact with a graphic does not select the graphic. For example, a swipe gesture that sweeps over an application icon optionally does not select the corresponding application when the gesture corresponding to selection is a tap. 
     Device  100  optionally also include one or more physical buttons, such as “home” or menu button  204 . As described previously, menu button  204  is, optionally, used to navigate to any application  136  in a set of applications that are, optionally, executed on device  100 . Alternatively, in some embodiments, the menu button is implemented as a soft key in a GUI displayed on touch screen  112 . 
     In some embodiments, device  100  includes touch screen  112 , menu button  204 , push button  206  for powering the device on/off and locking the device, volume adjustment button(s)  208 , subscriber identity module (SIM) card slot  210 , headset jack  212 , and docking/charging external port  124 . Push button  206  is, optionally, used to turn the power on/off on the device by depressing the button and holding the button in the depressed state for a predefined time interval; to lock the device by depressing the button and releasing the button before the predefined time interval has elapsed; and/or to unlock the device or initiate an unlock process. In an alternative embodiment, device  100  also accepts verbal input for activation or deactivation of some functions through microphone  113 . Device  100  also, optionally, includes one or more contact intensity sensors  165  for detecting intensity of contacts on touch screen  112  and/or one or more tactile output generators  167  for generating tactile outputs for a user of device  100 . 
       FIG. 3  is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface in accordance with some embodiments. Device  300  need not be portable. In some embodiments, device  300  is a laptop computer, a desktop computer, a tablet computer, a multimedia player device, a navigation device, an educational device (such as a child&#39;s learning toy), a gaming system, or a control device (e.g., a home or industrial controller). Device  300  typically includes one or more processing units (CPUs)  310 , one or more network or other communications interfaces  360 , memory  370 , and one or more communication buses  320  for interconnecting these components. Communication buses  320  optionally include circuitry (sometimes called a chipset) that interconnects and controls communications between system components. Device  300  includes input/output (I/O) interface  330  comprising display  340 , which is typically a touch screen display. I/O interface  330  also optionally includes a keyboard and/or mouse (or other pointing device)  350  and touchpad  355 , tactile output generator  357  for generating tactile outputs on device  300  (e.g., similar to tactile output generator(s)  167  described above with reference to  FIG. 1A ), sensors  359  (e.g., optical, acceleration, proximity, touch-sensitive, and/or contact intensity sensors similar to contact intensity sensor(s)  165  described above with reference to  FIG. 1A ). Memory  370  includes high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices; and optionally includes non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory  370  optionally includes one or more storage devices remotely located from CPU(s)  310 . In some embodiments, memory  370  stores programs, modules, and data structures analogous to the programs, modules, and data structures stored in memory  102  of portable multifunction device  100  ( FIG. 1A ), or a subset thereof. Furthermore, memory  370  optionally stores additional programs, modules, and data structures not present in memory  102  of portable multifunction device  100 . For example, memory  370  of device  300  optionally stores drawing module  380 , presentation module  382 , word processing module  384 , website creation module  386 , disk authoring module  388 , and/or spreadsheet module  390 , while memory  102  of portable multifunction device  100  ( FIG. 1A ) optionally does not store these modules. 
     Each of the above-identified elements in  FIG. 3  is, optionally, stored in one or more of the previously mentioned memory devices. Each of the above-identified modules corresponds to a set of instructions for performing a function described above. The above-identified modules or programs (e.g., sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules are, optionally, combined or otherwise rearranged in various embodiments. In some embodiments, memory  370  optionally stores a subset of the modules and data structures identified above. Furthermore, memory  370  optionally stores additional modules and data structures not described above. 
     Attention is now directed towards embodiments of user interfaces that are, optionally, implemented on, for example, portable multifunction device  100 . 
       FIG. 4A  illustrates an exemplary user interface for a menu of applications on portable multifunction device  100  in accordance with some embodiments. Similar user interfaces are, optionally, implemented on device  300 . In some embodiments, user interface  400  includes the following elements, or a subset or superset thereof:
         Signal strength indicator(s)  402  for wireless communication(s), such as cellular and Wi-Fi signals;   Time  404 ;   Bluetooth indicator  405 ;   Battery status indicator  406 ;   Tray  408  with icons for frequently used applications, such as:
           Icon  416  for telephone module  138 , labeled “Phone,” which optionally includes an indicator  414  of the number of missed calls or voicemail messages;   Icon  418  for e-mail client module  140 , labeled “Mail,” which optionally includes an indicator  410  of the number of unread e-mails;   Icon  420  for browser module  147 , labeled “Browser;” and   Icon  422  for video and music player module  152 , also referred to as iPod (trademark of Apple Inc.) module  152 , labeled “iPod;” and   
           Icons for other applications, such as:
           Icon  424  for IM module  141 , labeled “Messages;”   Icon  426  for calendar module  148 , labeled “Calendar;”   Icon  428  for image management module  144 , labeled “Photos;”   Icon  430  for camera module  143 , labeled “Camera;”   Icon  432  for online video module  155 , labeled “Online Video;”   Icon  434  for stocks widget  149 - 2 , labeled “Stocks;”   Icon  436  for map module  154 , labeled “Maps;”   Icon  438  for weather widget  149 - 1 , labeled “Weather;”   Icon  440  for alarm clock widget  149 - 4 , labeled “Clock;”   Icon  442  for workout support module  142 , labeled “Workout Support;”   Icon  444  for notes module  153 , labeled “Notes;” and   Icon  446  for a settings application or module, labeled “Settings,” which provides access to settings for device  100  and its various applications  136 .   
               

     It should be noted that the icon labels illustrated in  FIG. 4A  are merely exemplary. For example, icon  422  for video and music player module  152  is labeled “Music” or “Music Player.” Other labels are, optionally, used for various application icons. In some embodiments, a label for a respective application icon includes a name of an application corresponding to the respective application icon. In some embodiments, a label for a particular application icon is distinct from a name of an application corresponding to the particular application icon. 
       FIG. 4B  illustrates an exemplary user interface on a device (e.g., device  300 ,  FIG. 3 ) with a touch-sensitive surface  451  (e.g., a tablet or touchpad  355 ,  FIG. 3 ) that is separate from the display  450  (e.g., touch screen display  112 ). Device  300  also, optionally, includes one or more contact intensity sensors (e.g., one or more of sensors  359 ) for detecting intensity of contacts on touch-sensitive surface  451  and/or one or more tactile output generators  357  for generating tactile outputs for a user of device  300 . 
     Although some of the examples that follow will be given with reference to inputs on touch screen display  112  (where the touch-sensitive surface and the display are combined), in some embodiments, the device detects inputs on a touch-sensitive surface that is separate from the display, as shown in  FIG. 4B . In some embodiments, the touch-sensitive surface (e.g.,  451  in  FIG. 4B ) has a primary axis (e.g.,  452  in  FIG. 4B ) that corresponds to a primary axis (e.g.,  453  in  FIG. 4B ) on the display (e.g.,  450 ). In accordance with these embodiments, the device detects contacts (e.g.,  460  and  462  in  FIG. 4B ) with the touch-sensitive surface  451  at locations that correspond to respective locations on the display (e.g., in  FIG. 4B, 460  corresponds to  468  and  462  corresponds to  470 ). In this way, user inputs (e.g., contacts  460  and  462 , and movements thereof) detected by the device on the touch-sensitive surface (e.g.,  451  in  FIG. 4B ) are used by the device to manipulate the user interface on the display (e.g.,  450  in  FIG. 4B ) of the multifunction device when the touch-sensitive surface is separate from the display. It should be understood that similar methods are, optionally, used for other user interfaces described herein. 
     Additionally, while the following examples are given primarily with reference to finger inputs (e.g., finger contacts, finger tap gestures, finger swipe gestures), it should be understood that, in some embodiments, one or more of the finger inputs are replaced with input from another input device (e.g., a mouse-based input or stylus input). For example, a swipe gesture is, optionally, replaced with a mouse click (e.g., instead of a contact) followed by movement of the cursor along the path of the swipe (e.g., instead of movement of the contact). As another example, a tap gesture is, optionally, replaced with a mouse click while the cursor is located over the location of the tap gesture (e.g., instead of detection of the contact followed by ceasing to detect the contact). Similarly, when multiple user inputs are simultaneously detected, it should be understood that multiple computer mice are, optionally, used simultaneously, or a mouse and finger contacts are, optionally, used simultaneously. 
       FIG. 5A  illustrates exemplary personal electronic device  500 . Device  500  includes body  502 . In some embodiments, device  500  can include some or all of the features described with respect to devices  100  and  300  (e.g.,  FIGS. 1A-4B ). In some embodiments, device  500  has touch-sensitive display screen  504 , hereafter touch screen  504 . Alternatively, or in addition to touch screen  504 , device  500  has a display and a touch-sensitive surface. As with devices  100  and  300 , in some embodiments, touch screen  504  (or the touch-sensitive surface) optionally includes one or more intensity sensors for detecting intensity of contacts (e.g., touches) being applied. The one or more intensity sensors of touch screen  504  (or the touch-sensitive surface) can provide output data that represents the intensity of touches. The user interface of device  500  can respond to touches based on their intensity, meaning that touches of different intensities can invoke different user interface operations on device  500 . 
     Exemplary techniques for detecting and processing touch intensity are found, for example, in related applications: International Patent Application Serial No. PCT/US2013/040061, titled “Device, Method, and Graphical User Interface for Displaying User Interface Objects Corresponding to an Application,” filed May 8, 2013, published as WIPO Publication No. WO/2013/169849, and International Patent Application Serial No. PCT/US2013/069483, titled “Device, Method, and Graphical User Interface for Transitioning Between Touch Input to Display Output Relationships,” filed Nov. 11, 2013, published as WIPO Publication No. WO/2014/105276, each of which is hereby incorporated by reference in their entirety. 
     In some embodiments, device  500  has one or more input mechanisms  506  and  508 . Input mechanisms  506  and  508 , if included, can be physical. Examples of physical input mechanisms include push buttons and rotatable mechanisms. In some embodiments, device  500  has one or more attachment mechanisms. Such attachment mechanisms, if included, can permit attachment of device  500  with, for example, hats, eyewear, earrings, necklaces, shirts, jackets, bracelets, watch straps, chains, trousers, belts, shoes, purses, backpacks, and so forth. These attachment mechanisms permit device  500  to be worn by a user. 
       FIG. 5B  depicts exemplary personal electronic device  500 . In some embodiments, device  500  can include some or all of the components described with respect to  FIGS. 1A, 1B , and  3 . Device  500  has bus  512  that operatively couples I/O section  514  with one or more computer processors  516  and memory  518 . I/O section  514  can be connected to display  504 , which can have touch-sensitive component  522  and, optionally, intensity sensor  524  (e.g., contact intensity sensor). In addition, I/O section  514  can be connected with communication unit  530  for receiving application and operating system data, using Wi-Fi, Bluetooth, near field communication (NFC), cellular, and/or other wireless communication techniques. Device  500  can include input mechanisms  506  and/or  508 . Input mechanism  506  is, optionally, a rotatable input device or a depressible and rotatable input device, for example. Input mechanism  508  is, optionally, a button, in some examples. 
     Input mechanism  508  is, optionally, a microphone, in some examples. Personal electronic device  500  optionally includes various sensors, such as GPS sensor  532 , accelerometer  534 , directional sensor  540  (e.g., compass), gyroscope  536 , motion sensor  538 , and/or a combination thereof, all of which can be operatively connected to I/O section  514 . 
     Memory  518  of personal electronic device  500  can include one or more non-transitory computer-readable storage mediums, for storing computer-executable instructions, which, when executed by one or more computer processors  516 , for example, can cause the computer processors to perform the techniques described below, including processes  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  1800 ,  2000 ,  2200 ,  2500 ,  2700 ,  2900 ,  3100 ,  3300 ,  3500 ,  3700 ,  3900 ,  4100 ,  4300  ( FIGS. 8, 10, 12, 14, 16, 18, 20, 22, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43 ). A computer-readable storage medium can be any medium that can tangibly contain or store computer-executable instructions for use by or in connection with the instruction execution system, apparatus, or device. In some examples, the storage medium is a transitory computer-readable storage medium. In some examples, the storage medium is a non-transitory computer-readable storage medium. The non-transitory computer-readable storage medium can include, but is not limited to, magnetic, optical, and/or semiconductor storages. Examples of such storage include magnetic disks, optical discs based on CD, DVD, or Blu-ray technologies, as well as persistent solid-state memory such as flash, solid-state drives, and the like. Personal electronic device  500  is not limited to the components and configuration of  FIG. 5B , but can include other or additional components in multiple configurations. 
     As used here, the term “affordance” refers to a user-interactive graphical user interface object that is, optionally, displayed on the display screen of devices  100 ,  300 , and/or  500  ( FIGS. 1A, 3, and 5A-5B ). For example, an image (e.g., icon), a button, and text (e.g., hyperlink) each optionally constitute an affordance. 
     As used herein, the term “focus selector” refers to an input element that indicates a current part of a user interface with which a user is interacting. In some implementations that include a cursor or other location marker, the cursor acts as a “focus selector” so that when an input (e.g., a press input) is detected on a touch-sensitive surface (e.g., touchpad  355  in  FIG. 3  or touch-sensitive surface  451  in  FIG. 4B ) while the cursor is over a particular user interface element (e.g., a button, window, slider, or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations that include a touch screen display (e.g., touch-sensitive display system  112  in  FIG. 1A  or touch screen  112  in  FIG. 4A ) that enables direct interaction with user interface elements on the touch screen display, a detected contact on the touch screen acts as a “focus selector” so that when an input (e.g., a press input by the contact) is detected on the touch screen display at a location of a particular user interface element (e.g., a button, window, slider, or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations, focus is moved from one region of a user interface to another region of the user interface without corresponding movement of a cursor or movement of a contact on a touch screen display (e.g., by using a tab key or arrow keys to move focus from one button to another button); in these implementations, the focus selector moves in accordance with movement of focus between different regions of the user interface. Without regard to the specific form taken by the focus selector, the focus selector is generally the user interface element (or contact on a touch screen display) that is controlled by the user so as to communicate the user&#39;s intended interaction with the user interface (e.g., by indicating, to the device, the element of the user interface with which the user is intending to interact). For example, the location of a focus selector (e.g., a cursor, a contact, or a selection box) over a respective button while a press input is detected on the touch-sensitive surface (e.g., a touchpad or touch screen) will indicate that the user is intending to activate the respective button (as opposed to other user interface elements shown on a display of the device). 
     As used in the specification and claims, the term “characteristic intensity” of a contact refers to a characteristic of the contact based on one or more intensities of the contact. In some embodiments, the characteristic intensity is based on multiple intensity samples. The characteristic intensity is, optionally, based on a predefined number of intensity samples, or a set of intensity samples collected during a predetermined time period (e.g., 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10 seconds) relative to a predefined event (e.g., after detecting the contact, prior to detecting liftoff of the contact, before or after detecting a start of movement of the contact, prior to detecting an end of the contact, before or after detecting an increase in intensity of the contact, and/or before or after detecting a decrease in intensity of the contact). A characteristic intensity of a contact is, optionally, based on one or more of: a maximum value of the intensities of the contact, a mean value of the intensities of the contact, an average value of the intensities of the contact, a top 10 percentile value of the intensities of the contact, a value at the half maximum of the intensities of the contact, a value at the 90 percent maximum of the intensities of the contact, or the like. In some embodiments, the duration of the contact is used in determining the characteristic intensity (e.g., when the characteristic intensity is an average of the intensity of the contact over time). In some embodiments, the characteristic intensity is compared to a set of one or more intensity thresholds to determine whether an operation has been performed by a user. For example, the set of one or more intensity thresholds optionally includes a first intensity threshold and a second intensity threshold. In this example, a contact with a characteristic intensity that does not exceed the first threshold results in a first operation, a contact with a characteristic intensity that exceeds the first intensity threshold and does not exceed the second intensity threshold results in a second operation, and a contact with a characteristic intensity that exceeds the second threshold results in a third operation. In some embodiments, a comparison between the characteristic intensity and one or more thresholds is used to determine whether or not to perform one or more operations (e.g., whether to perform a respective operation or forgo performing the respective operation), rather than being used to determine whether to perform a first operation or a second operation. 
       FIG. 5C  illustrates detecting a plurality of contacts  552 A- 552 E on touch-sensitive display screen  504  with a plurality of intensity sensors  524 A- 524 D.  FIG. 5C  additionally includes intensity diagrams that show the current intensity measurements of the intensity sensors  524 A- 524 D relative to units of intensity. In this example, the intensity measurements of intensity sensors  524 A and  524 D are each 9 units of intensity, and the intensity measurements of intensity sensors  524 B and  524 C are each 7 units of intensity. In some implementations, an aggregate intensity is the sum of the intensity measurements of the plurality of intensity sensors  524 A- 524 D, which in this example is 32 intensity units. In some embodiments, each contact is assigned a respective intensity that is a portion of the aggregate intensity.  FIG. 5D  illustrates assigning the aggregate intensity to contacts  552 A- 552 E based on their distance from the center of force  554 . In this example, each of contacts  552 A,  552 B, and  552 E are assigned an intensity of contact of 8 intensity units of the aggregate intensity, and each of contacts  552 C and  552 D are assigned an intensity of contact of 4 intensity units of the aggregate intensity. More generally, in some implementations, each contact j is assigned a respective intensity Ij that is a portion of the aggregate intensity, A, in accordance with a predefined mathematical function, Ij=A·(Dj/ΣDi), where Dj is the distance of the respective contact j to the center of force, and ΣDi is the sum of the distances of all the respective contacts (e.g., i=1 to last) to the center of force. The operations described with reference to  FIGS. 5C-5D  can be performed using an electronic device similar or identical to device  100 ,  300 , or  500 . In some embodiments, a characteristic intensity of a contact is based on one or more intensities of the contact. In some embodiments, the intensity sensors are used to determine a single characteristic intensity (e.g., a single characteristic intensity of a single contact). It should be noted that the intensity diagrams are not part of a displayed user interface, but are included in  FIGS. 5C-5D  to aid the reader. 
     In some embodiments, a portion of a gesture is identified for purposes of determining a characteristic intensity. For example, a touch-sensitive surface optionally receives a continuous swipe contact transitioning from a start location and reaching an end location, at which point the intensity of the contact increases. In this example, the characteristic intensity of the contact at the end location is, optionally, based on only a portion of the continuous swipe contact, and not the entire swipe contact (e.g., only the portion of the swipe contact at the end location). In some embodiments, a smoothing algorithm is, optionally, applied to the intensities of the swipe contact prior to determining the characteristic intensity of the contact. For example, the smoothing algorithm optionally includes one or more of: an unweighted sliding-average smoothing algorithm, a triangular smoothing algorithm, a median filter smoothing algorithm, and/or an exponential smoothing algorithm. In some circumstances, these smoothing algorithms eliminate narrow spikes or dips in the intensities of the swipe contact for purposes of determining a characteristic intensity. 
     The intensity of a contact on the touch-sensitive surface is, optionally, characterized relative to one or more intensity thresholds, such as a contact-detection intensity threshold, a light press intensity threshold, a deep press intensity threshold, and/or one or more other intensity thresholds. In some embodiments, the light press intensity threshold corresponds to an intensity at which the device will perform operations typically associated with clicking a button of a physical mouse or a trackpad. In some embodiments, the deep press intensity threshold corresponds to an intensity at which the device will perform operations that are different from operations typically associated with clicking a button of a physical mouse or a trackpad. In some embodiments, when a contact is detected with a characteristic intensity below the light press intensity threshold (e.g., and above a nominal contact-detection intensity threshold below which the contact is no longer detected), the device will move a focus selector in accordance with movement of the contact on the touch-sensitive surface without performing an operation associated with the light press intensity threshold or the deep press intensity threshold. Generally, unless otherwise stated, these intensity thresholds are consistent between different sets of user interface figures. 
     An increase of characteristic intensity of the contact from an intensity below the light press intensity threshold to an intensity between the light press intensity threshold and the deep press intensity threshold is sometimes referred to as a “light press” input. An increase of characteristic intensity of the contact from an intensity below the deep press intensity threshold to an intensity above the deep press intensity threshold is sometimes referred to as a “deep press” input. An increase of characteristic intensity of the contact from an intensity below the contact-detection intensity threshold to an intensity between the contact-detection intensity threshold and the light press intensity threshold is sometimes referred to as detecting the contact on the touch-surface. A decrease of characteristic intensity of the contact from an intensity above the contact-detection intensity threshold to an intensity below the contact-detection intensity threshold is sometimes referred to as detecting liftoff of the contact from the touch-surface. In some embodiments, the contact-detection intensity threshold is zero. In some embodiments, the contact-detection intensity threshold is greater than zero. 
     In some embodiments described herein, one or more operations are performed in response to detecting a gesture that includes a respective press input or in response to detecting the respective press input performed with a respective contact (or a plurality of contacts), where the respective press input is detected based at least in part on detecting an increase in intensity of the contact (or plurality of contacts) above a press-input intensity threshold. In some embodiments, the respective operation is performed in response to detecting the increase in intensity of the respective contact above the press-input intensity threshold (e.g., a “down stroke” of the respective press input). In some embodiments, the press input includes an increase in intensity of the respective contact above the press-input intensity threshold and a subsequent decrease in intensity of the contact below the press-input intensity threshold, and the respective operation is performed in response to detecting the subsequent decrease in intensity of the respective contact below the press-input threshold (e.g., an “up stroke” of the respective press input). 
       FIGS. 5E-5H  illustrate detection of a gesture that includes a press input that corresponds to an increase in intensity of a contact  562  from an intensity below a light press intensity threshold (e.g., “IT L ”) in  FIG. 5E , to an intensity above a deep press intensity threshold (e.g., “IT D ”) in  FIG. 5H . The gesture performed with contact  562  is detected on touch-sensitive surface  560  while cursor  576  is displayed over application icon  572 B corresponding to App 2, on a displayed user interface  570  that includes application icons  572 A- 572 D displayed in predefined region  574 . In some embodiments, the gesture is detected on touch-sensitive display  504 . The intensity sensors detect the intensity of contacts on touch-sensitive surface  560 . The device determines that the intensity of contact  562  peaked above the deep press intensity threshold (e.g., “IT D ”). Contact  562  is maintained on touch-sensitive surface  560 . In response to the detection of the gesture, and in accordance with contact  562  having an intensity that goes above the deep press intensity threshold (e.g., “IT D ”) during the gesture, reduced-scale representations  578 A- 578 C (e.g., thumbnails) of recently opened documents for App 2 are displayed, as shown in  FIGS. 5F-5H . In some embodiments, the intensity, which is compared to the one or more intensity thresholds, is the characteristic intensity of a contact. It should be noted that the intensity diagram for contact  562  is not part of a displayed user interface, but is included in  FIGS. 5E-5H  to aid the reader. 
     In some embodiments, the display of representations  578 A- 578 C includes an animation. For example, representation  578 A is initially displayed in proximity of application icon  572 B, as shown in  FIG. 5F . As the animation proceeds, representation  578 A moves upward and representation  578 B is displayed in proximity of application icon  572 B, as shown in  FIG. 5G . Then, representations  578 A moves upward,  578 B moves upward toward representation  578 A, and representation  578 C is displayed in proximity of application icon  572 B, as shown in  FIG. 5H . Representations  578 A- 578 C form an array above icon  572 B. In some embodiments, the animation progresses in accordance with an intensity of contact  562 , as shown in  FIGS. 5F-5G , where the representations  578 A- 578 C appear and move upwards as the intensity of contact  562  increases toward the deep press intensity threshold (e.g., “ITS”). In some embodiments, the intensity, on which the progress of the animation is based, is the characteristic intensity of the contact. The operations described with reference to  FIGS. 5E-5H  can be performed using an electronic device similar or identical to device  100 ,  300 , or  500 . 
     In some embodiments, the device employs intensity hysteresis to avoid accidental inputs sometimes termed “jitter,” where the device defines or selects a hysteresis intensity threshold with a predefined relationship to the press-input intensity threshold (e.g., the hysteresis intensity threshold is X intensity units lower than the press-input intensity threshold or the hysteresis intensity threshold is 75%, 90%, or some reasonable proportion of the press-input intensity threshold). Thus, in some embodiments, the press input includes an increase in intensity of the respective contact above the press-input intensity threshold and a subsequent decrease in intensity of the contact below the hysteresis intensity threshold that corresponds to the press-input intensity threshold, and the respective operation is performed in response to detecting the subsequent decrease in intensity of the respective contact below the hysteresis intensity threshold (e.g., an “up stroke” of the respective press input). Similarly, in some embodiments, the press input is detected only when the device detects an increase in intensity of the contact from an intensity at or below the hysteresis intensity threshold to an intensity at or above the press-input intensity threshold and, optionally, a subsequent decrease in intensity of the contact to an intensity at or below the hysteresis intensity, and the respective operation is performed in response to detecting the press input (e.g., the increase in intensity of the contact or the decrease in intensity of the contact, depending on the circumstances). 
     For ease of explanation, the descriptions of operations performed in response to a press input associated with a press-input intensity threshold or in response to a gesture including the press input are, optionally, triggered in response to detecting either: an increase in intensity of a contact above the press-input intensity threshold, an increase in intensity of a contact from an intensity below the hysteresis intensity threshold to an intensity above the press-input intensity threshold, a decrease in intensity of the contact below the press-input intensity threshold, and/or a decrease in intensity of the contact below the hysteresis intensity threshold corresponding to the press-input intensity threshold. Additionally, in examples where an operation is described as being performed in response to detecting a decrease in intensity of a contact below the press-input intensity threshold, the operation is, optionally, performed in response to detecting a decrease in intensity of the contact below a hysteresis intensity threshold corresponding to, and lower than, the press-input intensity threshold. 
     As used herein, an “installed application” refers to a software application that has been downloaded onto an electronic device (e.g., devices  100 ,  300 , and/or  500 ) and is ready to be launched (e.g., become opened) on the device. In some embodiments, a downloaded application becomes an installed application by way of an installation program that extracts program portions from a downloaded package and integrates the extracted portions with the operating system of the computer system. 
     As used herein, the terms “open application” or “executing application” refer to a software application with retained state information (e.g., as part of device/global internal state  157  and/or application internal state  192 ). An open or executing application is, optionally, any one of the following types of applications:
         an active application, which is currently displayed on a display screen of the device that the application is being used on;   a background application (or background processes), which is not currently displayed, but one or more processes for the application are being processed by one or more processors; and   a suspended or hibernated application, which is not running, but has state information that is stored in memory (volatile and non-volatile, respectively) and that can be used to resume execution of the application.       

     As used herein, the term “closed application” refers to software applications without retained state information (e.g., state information for closed applications is not stored in a memory of the device). Accordingly, closing an application includes stopping and/or removing application processes for the application and removing state information for the application from the memory of the device. Generally, opening a second application while in a first application does not close the first application. When the second application is displayed and the first application ceases to be displayed, the first application becomes a background application. 
     Attention is now directed towards embodiments of user interfaces (“UI”) and associated processes that are implemented on an electronic device, such as portable multifunction device  100 , device  300 , or device  500 . 
       FIG. 6  illustrates exemplary devices connected via one or more communication channels to participate in a transaction in accordance with some embodiments. One or more exemplary electronic devices (e.g., devices  100 ,  300 , and  500 ) are configured to optionally detect input (e.g., a particular user input, an NFC field) and optionally transmit payment information (e.g., using NFC). The one or more electronic devices optionally include NFC hardware and are configured to be NFC-enabled. 
     The electronic devices (e.g., devices  100 ,  300 , and  500 ) are optionally configured to store payment account information associated with each of one or more payment accounts. Payment account information includes, for example, one or more of: a person&#39;s or company&#39;s name, a billing address, a login, a password, an account number, an expiration date, a security code, a telephone number, a bank associated with the payment account (e.g., an issuing bank), and a card network identifier. In some examples, payment account information includes include an image, such as a picture of a payment card (e.g., taken by the device and/or received at the device). In some examples, the electronic devices receive user input including at least some payment account information (e.g., receiving user-entered credit, debit, account, or gift card number and expiration date). In some examples, the electronic devices detect at least some payment account information from an image (e.g., of a payment card captured by a camera sensor of the device). In some examples, the electronic devices receive at least some payment account information from another device (e.g., another user device or a server). In some examples, the electronic device receives payment account information from a server associated with another service for which an account for a user or user device previously made a purchase or identified payment account data (e.g., an app for renting or selling audio and/or video files). 
     In some embodiments, a payment account is added to an electronic device (e.g., device  100 ,  300 , and  500 ), such that payment account information is securely stored on the electronic device. In some examples, after a user initiates such process, the electronic device transmits information for the payment account to a transaction-coordination server, which then communicates with a server operated by a payment network for the account (e.g., a payment server) to ensure a validity of the information. The electronic device is optionally configured to receive a script from the server that allows the electronic device to program payment information for the account onto the secure element. 
     In some embodiments, communication among electronic devices  100 ,  300 , and  500  facilitates transactions (e.g., generally or specific transactions). For example, a first electronic device (e.g.,  100 ) can serve as a provisioning or managing device, and can send notifications of new or updated payment account data (e.g., information for a new account, updated information for an existing account, and/or an alert pertaining to an existing account) to a second electronic device (e.g.,  500 ). In another example, a first electronic device (e.g.,  100 ) can send data to a second election device, wherein the data reflects information about payment transactions facilitated at the first electronic device. The information optionally includes one or more of: a payment amount, an account used, a time of purchase, and whether a default account was changed. The second device (e.g.,  500 ) optionally uses such information to update a default payment account (e.g., based on a learning algorithm or explicit user input). 
     Electronic devices (e.g.,  100 ,  300 ,  500 ) are configured to communicate with each other over any of a variety of networks. For example, the devices communicate using a Bluetooth connection  608  (e.g., which includes a traditional Bluetooth connection or a Bluetooth Low Energy connection) or using a WiFi network  606 . Communications among user devices are, optionally, conditioned to reduce the possibility of inappropriately sharing information across devices. For example, communications relating to payment information requires that the communicating devices be paired (e.g., be associated with each other via an explicit user interaction) or be associated with a same user account. 
     In some embodiments, an electronic device (e.g.,  100 ,  300 ,  500 ) is used to communicate with a point-of-sale (POS) payment terminal  600 , which is optionally NFC-enabled. The communication optionally occurs using a variety of communication channels and/or technologies. In some examples, electronic device (e.g.,  100 ,  300 ,  500 ) communicates with payment terminal  600  using an NFC channel  610 . In some examples, payment terminal  600  communicates with an electronic device (e.g.,  100 ,  300 ,  500 ) using a peer-to-peer NFC mode. Electronic device (e.g.,  100 ,  300 ,  500 ) is optionally configured transmit a signal to payment terminal  600  that includes payment information for a payment account (e.g., a default account or an account selected for the particular transaction). 
     In some embodiments, proceeding with a transaction includes transmitting a signal that includes payment information for an account, such as a payment account. In some embodiments, proceeding with the transaction includes reconfiguring the electronic device (e.g.,  100 ,  300 ,  500 ) to respond as a contactless payment card, such as an NFC-enabled contactless payment card, and then transmitting credentials of the account via NFC, such as to payment terminal  600 . In some embodiments, subsequent to transmitting credentials of the account via NFC, the electronic device reconfigures to not respond as a contactless payment card (e.g., requiring authorization before again reconfigured to respond as a contactless payment card via NFC). 
     In some embodiments, generation of and/or transmission of the signal is controlled by a secure element in the electronic device (e.g.,  100 ,  300 ,  500 ). The secure element optionally requires a particular user input prior to releasing payment information. For example, the secure element optionally requires detection that the electronic device is being worn, detection of a button press, detection of entry of a passcode, detection of a touch, detection of one or more option selections (e.g., received while interacting with an application), detection of a fingerprint signature, detection of a voice or voice command, and or detection of a gesture or movement (e.g., rotation or acceleration). In some examples, if a communication channel (e.g., an NFC communication channel) with another device (e.g., payment terminal  600 ) is established within a defined time period from detection of the input, the secure element releases payment information to be transmitted to the other device (e.g., payment terminal  600 ). In some examples, the secure element is a hardware component that controls release of secure information. In some examples, the secure element is a software component that controls release of secure information. 
     In some embodiments, protocols related to transaction participation depend on, for example, device types. For example, a condition for generating and/or transmitting payment information can be different for a wearable device (e.g., device  500 ) and a phone (e.g., device  100 ). For example, a generation and/or transmission condition for a wearable device includes detecting that a button has been pressed (e.g., after a security verification), while a corresponding condition for a phone does not require button-depression and instead requires detection of particular interaction with an application. In some examples, a condition for transmitting and/or releasing payment information includes receiving particular input on each of multiple devices. For example, release of payment information optionally requires detection of a fingerprint and/or passcode at the device (e.g., device  100 ) and detection of a mechanical input (e.g., button press) on another device (e.g., device  500 ). 
     Payment terminal  600  optionally uses the payment information to generate a signal to transmit to a payment server  604  to determine whether the payment is authorized. Payment server  604  optionally includes any device or system configured to receive payment information associated with a payment account and to determine whether a proposed purchase is authorized. In some examples, payment server  604  includes a server of an issuing bank. Payment terminal  600  communicates with payment server  604  directly or indirectly via one or more other devices or systems (e.g., a server of an acquiring bank and/or a server of a card network). 
     Payment server  604  optionally uses at least some of the payment information to identify a user account from among a database of user accounts (e.g.,  602 ). For example, each user account includes payment information. An account is, optionally, located by locating an account with particular payment information matching that from the POS communication. In some examples, a payment is denied when provided payment information is not consistent (e.g., an expiration date does not correspond to a credit, debit or gift card number) or when no account includes payment information matching that from the POS communication. 
     In some embodiments, data for the user account further identifies one or more restrictions (e.g., credit limits); current or previous balances; previous transaction dates, locations and/or amounts; account status (e.g., active or frozen), and/or authorization instructions. In some examples, the payment server (e.g.,  604 ) uses such data to determine whether to authorize a payment. For example, a payment server denies a payment when a purchase amount added to a current balance would result in exceeding an account limit, when an account is frozen, when a previous transaction amount exceeds a threshold, or when a previous transaction count or frequency exceeds a threshold. 
     In some embodiments, payment server  604  responds to POS payment terminal  600  with an indication as to whether a proposed purchase is authorized or denied. In some examples, POS payment terminal  600  transmits a signal to the electronic device (e.g.,  100 ,  300 ,  500 ) to identify the result. For example, POS payment terminal  600  sends a receipt to the electronic device (e.g.,  100 ,  300 ,  500 ) when a purchase is authorized (e.g., via a transaction-coordination server that manages a transaction app on the user device). In some instances, POS payment terminal  600  presents an output (e.g., a visual or audio output) indicative of the result. Payment can be sent to a merchant as part of the authorization process or can be subsequently sent. 
     In some embodiments, the electronic device (e.g.,  100 ,  300 ,  500 ) participates in a transaction that is completed without involvement of POS payment terminal  600 . For example, upon detecting that a mechanical input has been received, a secure element in the electronic device (e.g.,  100 ,  300 ,  500 ) releases payment information to allow an application on the electronic device to access the information (e.g., and to transmit the information to a server associated with the application). 
     In some embodiments, the electronic device (e.g.,  100 ,  300 ,  500 ) is in a locked state or an unlocked state. In the locked state, the electronic device is powered on and operational but is prevented from performing a predefined set of operations in response to the user input. The predefined set of operations optionally includes navigation between user interfaces, activation or deactivation of a predefined set of functions, and activation or deactivation of certain applications. The locked state can be used to prevent unintentional or unauthorized use of some functionality of the electronic device or activation or deactivation of some functions on the electronic device. In the unlocked state, the electronic device  100  is power on and operational and is not prevented from performing at least a portion of the predefined set of operations that cannot be performed while in the locked state. 
     When the device is in the locked state, the device is said to be locked. In some embodiments, the device in the locked state optionally responds to a limited set of user inputs, including input that corresponds to an attempt to transition the device to the unlocked state or input that corresponds to powering the device off. 
     In some examples, a secure element (e.g.,  115 ) is a hardware component (e.g., a secure microcontroller chip) configured to securely store data or an algorithm such that the securely stored data is not accessible by the device without proper authentication information from a user of the device. Keeping the securely stored data in a secure element that is separate from other storage on the device prevents access to the securely stored data even if other storage locations on the device are compromised (e.g., by malicious code or other attempts to compromise information stored on the device). In some examples, the secure element provides (or releases) payment information (e.g., an account number and/or a transaction-specific dynamic security code). In some examples, the secure element provides (or releases) the payment information in response to the device receiving authorization, such as a user authentication (e.g., fingerprint authentication; passcode authentication; detecting double-press of a hardware button when the device is in an unlocked state, and optionally, while the device has been continuously on a user&#39;s wrist since the device was unlocked by providing authentication credentials to the device, where the continuous presence of the device on the user&#39;s wrist is determined by periodically checking that the device is in contact with the user&#39;s skin). For example, the device detects a fingerprint at a fingerprint sensor (e.g., a fingerprint sensor integrated into a button) of the device. The device determines whether the fingerprint is consistent with a registered fingerprint. In accordance with a determination that the fingerprint is consistent with the registered fingerprint, the secure element provides (or releases) payment information. In accordance with a determination that the fingerprint is not consistent with the registered fingerprint, the secure element forgoes providing (or releasing) payment information. 
     Attention is now directed towards embodiments of user interfaces (“UI”) and associated processes that are implemented on an electronic device, such as portable multifunction device  100 , device  300 , or device  500 . 
       FIGS. 7A-7S  illustrate exemplary user interfaces for providing an instructional tutorial for enrolling a biometric feature on an electronic device (e.g., device  100 , device  300 , or device  500 ), in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIG. 8 . 
       FIG. 7A  illustrates an electronic device  700  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary example illustrated in  FIGS. 7A-7S , electronic device  700  is a smartphone. In other examples, electronic device  1500  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  700  has a display  702 , one or more input devices (e.g., touchscreen of display  1502 , a button, a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  703 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, one or more of the biometric sensor is a biometric sensor (e.g., facial recognition sensor), such as those described in U.S. Ser. No. 14/341,860, “Overlapping Pattern Projector,” filed Jul. 14, 2014, U.S. Pub. No. 2016/0025993 and U.S. Ser. No. 13/810,451, “Scanning Projects and Image Capture Modules For 3D Mapping,” U.S. Pat. No. 9,098,931, which are hereby incorporated by reference in their entirety for any purpose. In some examples, the electronic device includes a depth camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the subject during capture of the image by a visible light camera and a depth camera (e.g., an IR camera) and the information from the depth camera and the visible light camera are used to determine a depth map of different portions of subject captured by the visible light camera. In some examples, the lighting effects described herein are displayed using disparity information from two cameras (e.g., two visual light cameras) for rear facing images and using depth information from a depth camera combined with image data from a visual light camera for front facing images (e.g., selfie images). In some examples, the same user interface is used when the two visual light cameras are used to determine the depth information and when the depth camera is used to determine the depth information, providing the user with a consistent experience, even when using dramatically different technologies to determine the information that is used when generating the lighting effects. In some examples, while displaying the camera user interface with one of the lighting effects applied, the device detects selection of a camera switching affordance and switches from the front facing cameras (e.g., a depth camera and a visible light camera) to the rear facing cameras (e.g., two visible light cameras that are spaced apart from each other) (or vice versa) while maintaining display of the user interface controls for applying the lighting effect and replacing display of the field of view of the front facing cameras to the field of view of the rear facing cameras (or vice versa). 
     As shown in  FIG. 7A , device  700  displays device set-up user interface  702  on display  701 . In some examples, device set-up user interface  702  is displayed when device  700  is first powered up by a user (e.g., when a factory-sealed device is first powered on). In some examples, device-set-up user interface  702  is displayed upon resetting device  700  to factory settings. Phone set-up user interface  702  includes one or more prompts  704 . In the example of  FIG. 7A , prompt  704  is plain text that prompts the user to proceed with initial device set-up (e.g., language selection, authentication measures, etc.). Device set-up interface  702  includes one or more affordances, such as continue affordance  706  and skip affordance  708 . In some examples, in response to detecting a user input corresponding to activation of skip affordance  708 , device  700  optionally displays a primary user interface, such as the user interface of  FIG. 4A , without set-up of one or more features. 
     As illustrated in  FIG. 7B , while displaying the set-up interface  702 , the electronic device  700  detects activation (e.g., selection) of the continue affordance  706 . In some examples, the activation is a tap gesture  710  on contact area  710  at continue affordance  706 . In some examples where display  700  is a touch sensitive display, the activation of the continue affordance is a touch, swipe, or other gesture on the display surface at contact area  710 . In some examples where display  700  is not touch sensitive, the user input is a keyboard input or activation of continue affordance  706  with a focus selector (e.g., a mouse cursor). 
     In response to detecting activation of continue affordance  706 , the device displays face authentication tutorial interface  712  as shown in  FIG. 7C . In some examples, face authentication set-up interface  712  is displayed in response to finishing a prior stage of a device set-up user interface process, or in response to selecting a face authentication enrollment option in a settings user interface. Face authentication set-up interface  712  includes one or more prompts  714 , continue affordance  716  and later affordance  718 . In the example of  FIG. 7C , prompt  714  is plain text indicating that the user has an option set up face authentication in lieu of a numerical passcode. Face authentication set-up interface  712  also includes a graphical representation of a face (e.g., biometric authentication glyph  720 ) that is displayed within framing element  722 . In the example of  FIG. 7C , framing element  722  is a rectangular shape surrounding biometric authentication glyph  720  such that only the corners of the rectangle are displayed. In some examples, the framing element is, optionally, a solid rectangle or any other shape (e.g., a circle or oval) surrounding glyph  720 . In some examples, framing element  722  helps indicate to a user how to properly position their face relative to biometric sensor  703  in combination with the additional features described below. 
     Turning to  FIG. 7D , device  700  detects activation (e.g., selection) of the continue affordance  716 . In some examples, the activation is a tap gesture  724  at continue affordance  716 . In some examples where display  701  is a touch sensitive display, the activation of the continue affordance is a touch, swipe, or other gesture on the display surface at contact area  724 . In some examples where display  701  is not touch sensitive, the user input is a keyboard input or activation of continue affordance  716  with a focus selector (e.g., a mouse cursor). 
     In response to detecting selection of continue affordance  716 , device  700  displays (e.g., replaces the display of prompt  714  with) prompt  726 , as illustrated in  FIG. 7E . Additionally, the device replaces the display of continue affordance  716  with start affordance  728 . Upon selection of continue affordance  716 , device  700  maintains (e.g., continues to) display glyph  720  and framing element  722 . 
     Turning to  FIG. 7F , device  700  detects activation (e.g., selection) of start affordance  728 . In some examples, the activation is a tap gesture  730  at start affordance  7728 . Activation of start affordance  728  optionally indicates a user request to initiate face authentication enrollment (e.g., set-up) process. 
     As shown in  FIGS. 7H-7Q , device  700  displays face authentication tutorial interface  732  in response to detecting selection of start affordance  728 . Concurrently, the device displays an instructional animation (e.g., a tutorial) that indicates to the user how to properly position and move his or her face relative to biometric sensor  703  such that device  700  will be able to gather sufficient biometric (e.g., facial imaging) data needed for secure (e.g., biometric) authentication. The details of the tutorial interface and instructional animation are described below. 
     As illustrated in  FIGS. 7G-7H , device  700  alters the display of framing element  722  to become a single, continuous framing element  723  that surrounds glyph  720 . As shown in  FIG. 7G , the device  700  optionally rounds each corner of framing element  722  into portion of a circle and merge and/or contract the portions to form a continuous circle (e.g., framing element  723  as shown in  FIG. 7H ) surrounding glyph  720 . 
     As shown in  FIG. 7H , device  700  concurrently displays instructional progress meter  734  proximate to and/or surrounding glyph  720 . In the example of  FIG. 7H , instructional progress meter  734  is composed of a set of progress elements (e.g., progress ticks  734   a ,  734   b , and  734   c ) that are evenly distributed around glyph  720 . In the example of  FIG. 7H , progress ticks  734   a ,  734   b , and  734   c  are equidistant and extend radially outward from glyph  720 , for instance, forming a circle around it. In some examples, these progress elements are, optionally, dots, circles, line segments, or any other suitable discrete elements. In some examples, these progress elements are, optionally, arranged around glyph  720  in square, rectangular, elliptical, or any other suitable pattern. 
     While displaying face authentication tutorial interface  732  (e.g., glyph surrounded by framing element  723  and instructional progress meter  734 ), device  700  begins to display an instructional animation illustrating the process of enrolling a user&#39;s facial data, as shown in  FIG. 7I . As described in more detail below with reference to  FIGS. 7I-7P , device  700  displays movement of glyph  720  in a circular motion and corresponding advancement of instructional progress meter  734  to emulate successful face authentication. 
     At the start of the instructional animation, device  700  overlays orientation guide  736  on top of the display of glyph  720 . In the example of  FIG. 7I , orientation guide  736  is a pair of intersecting curved lines (e.g., crosshairs) that extend from framing element  723  and glyph  720  such that they appear to bulge outwards from the plane of the display (e.g., in a simulated z-direction). In some examples, in combination with circular framing element  723 , the arcs of orientation, guide  736  give the otherwise two-dimensional glyph  720  a three-dimensional appearance, as if it were located on the surface of a sphere. In general, the instructional animation maintains orientation guide  736  at a fixed position relative to the center of glyph  720  such that the orientation guide appears to rotate and tilt along with (e.g., in the same directions as) the facial representation. In some examples, glyph  720  itself is a three-dimensional representation of a face, such as a three-dimensional line drawing with lines at a simulated z-height. In such examples, orientation guide  736  is, optionally, omitted. In this case, when the facial representation tilts in different directions, the lines at different z-heights appear to move relative to one another based on a simulated parallax effect to give the appearance of three-dimensional movement. 
     Device  700  begins the instructional animation on face authentication tutorial interface  732  by displaying movement (e.g., rotation and/or tilt) of glyph  720  and orientation guide  736  in a first direction (e.g., up, down, left, or right). In the example of  FIG. 7I , glyph  720  and the overlaid orientation guide  736  tilt to the right relative to a vertical axis extending from the plane of display  700 . Tilting glyph  720  in this manner optionally reveals part of the simulated face (e.g., the left side of the face) and hide another part of the simulated face (e.g., the right side of the face) to further give the appearance of a three-dimensional head tilting or rotating in a particular direction. 
     As illustrated in  FIG. 7I , device  700  changes the appearance of a subset of the progress elements as glyph  720  (and/or orientation guide  736 ) tilts towards them. In particular, progress elements in meter portion  738  optionally elongates and/or changes color from their initial state when the facial graphic tilts towards them. This elongation and/or color change is, optionally, more pronounced as glyph  720  tilts further in their direction. In some examples, progress elements in meter portion  738  optionally changes in appearance in other manners as well. For example, additionally and/or alternatively, the line thickness, number, or pattern of the progress elements optionally change. Changing the appearance of progress elements in this manner indicates to the user that biometric sensor  703  is configured to capture image data of a corresponding portion of the face when oriented in that direction. While displaying the instructional animation, device  700  maintains the display progress elements towards which the face graphic has not yet been tilted (e.g., elements of meter portion  740 ) in an initial state. In the example of  FIG. 7I , device  700  displays progress elements in the initial state as unfilled outlines. 
     In some examples, device  700  thereafter rotates glyph  720  about a second axis parallel to the plane of the display such that the simulated face appears to tilt upwards or downwards. In the example of  FIG. 7J , glyph  720  appears tilted upwards from its position in  FIG. 7I  such that the simulated face is pointing up and to the right. While rotating glyph  720  in this manner, device  700  changes the appearance of corresponding meter portion  740 , which was previously in the initial state, as shown in  FIG. 7I . The device changes the appearance of meter portion  740  in the same manner as described above with respect to  FIG. 7I  (e.g., by elongating and/or changing color of progress elements in this portion of the instructional progress meter). Concurrently, device  700  transitions progress elements in meter portion  738 , corresponding to the portion of the facial representation that was enrolled in  FIG. 7I , to a second state. Progress elements in the success state (e.g., the progress elements in meter portion  738 ) differ in shape, color, line width, etc. from progress elements in the initial state. In the example of  FIG. 7I , progress elements in the success state are displayed with the same size and width of progress elements in the initial state (e.g., progress elements in meter portion  742 ), but are darkened and/or filled in to indicate that the facial representation has already been oriented in that direction. 
       FIG. 7K  illustrates further tilt and/or rotation of glyph  720  and orientation guide  736  until the simulated face appears to be looking upwards. As described above, device  700  changes appearance (e.g., elongates and/or changes color) of progress elements in meter portion  742  as glyph  720  is oriented in their direction. Concurrently, device  700  transitions progress elements in meter portion  740  to the success state after the simulated face was previously, but is no longer oriented in their direction. Progress elements in meter portion  738  remain in the success state. In general, the appearance of progress elements that have been transitioned to the success state is not modified thereafter. In this manner, device  700  changes the appearance of elements in instructional progress meter  734  in response to displaying movement of glyph  720 . 
     In some examples, during the instructional animation, device  700  optionally continues to display rotation and/or tilt of glyph  720  until it has displayed a complete circular (e.g., clockwise, counterclockwise) motion of simulated face (e.g., until glyph  720  returns to the right-tilt orientation shown in  FIG. 7I ). Likewise, device  700  incrementally transitions elements of instructional progress meter  734  to the success state as glyph  720  is rotated past them, as described above. After displaying a full rotation of the simulated face, the device displays all progress elements of instructional progress meter  734  in the success state, as shown in  FIG. 7L . In some examples, device  700  ceases to display orientation guide  736  and returns glyph  720  to its initial position after a full rotation is displayed. 
     After all progress elements of instructional progress meter  724  have been transitioned to the success state, device  700  transitions progress meter  734  (e.g., the progress meter itself) to a authentication-success state, such as a solid circle surrounding glyph  720 . Displaying progress meter  724  in the authentication-success state optionally indicates successful face authentication set up. With reference to  FIGS. 7L-70 , device  700  transitions display of the discrete progress tick of instructional progress meter  734  to the authentication-success state by shortening each progress tick and merging them together into a continuous, solid circle (e.g., success-state meter  744 ) surrounding glyph  720 . In the example of  FIGS. 70 and 7P , the circle contracts around glyph  720  until the radius of success-state meter  744  is substantially the same as the radius of framing element  723  (e.g., as shown in  FIG. 7P ). 
     As shown in  FIGS. 7I-7Q , face authentication tutorial interface  732  also includes start affordance  746  that is, optionally, displayed throughout the face authentication tutorial. In some examples, start affordance  746  is enabled for activation after the instructional animation is complete (e.g., after device  700  displays instructional progress meter  734  in the authentication-success state of  FIG. 7Q ). In other examples, start affordance  746  is enabled for activation any time during display of the face authentication tutorial animation prior to completion of the instruction animation. 
     Turning now to  FIG. 7Q , device  700  detects activation (e.g., selection) of start affordance  746 . In some examples, the activation is a user input that corresponds to a request to begin face authentication set-up. In response to detecting activation of start affordance  746 , device  700  replaces the display of glyph  720  with an image  750  of the user&#39;s face captured by biometric sensor  703  as shown in  FIG. 7R . In some examples, image  748  is a live preview of the field of view of biometric sensor  703 . In other examples, image  750  is a wire-frame representation of the user&#39;s face based on movement of the user&#39;s face in the field of view of the optical sensors. Thus, image  750  changes (e.g., continually updates) as the position and orientation of the user&#39;s face relative to biometric sensor changes. 
     As shown in  FIG. 7R , device  700  also displays positioning element  752  around user image  750 . In some examples, positioning element  752  optionally has similar or identical visual properties as framing element  722  that was initially positioned surrounding glyph  720  in  FIGS. 7C-7F . In some examples, the positioning element is displayed to emphasize a predetermined portion of the display of the electronic device, indicating where the user should position his or her face relative to biometric sensors for subsequent face authentication set-up. In some examples, the positioning element a shape (e.g., a square) that at least partially partitions the predetermined display portion from the other parts of the display. Device  700  also displays prompt  754 , text that prompts the user to move his/or her face relative to the optical sensors such that user image  750  appears inside positioning element  750 . 
     Turning now to  FIG. 7S , in response to detecting that user image  750  has been properly positioned within positioning element  750  (e.g., the user&#39;s face is properly aligned with biometric sensor  703 ), device  700  displays face authentication enrollment interface  756 . In the example of  FIG. 7S , face authentication enrollment interface  756  includes progress meter  758  and user image  760 . In some examples, enrollment interface  756  includes orientation guide  762 , a set of curved lines (e.g., crosshairs) that appear to extend out of the plane of the display to Progress meter  758  optionally has some or all of the features of instructional progress indicator  734  that is displayed during the face authentication tutorial animation. In the example of  FIG. 7S , progress meter  758  also includes a set of progress elements (e.g., progress ticks  758   a ,  758   b , and  758   c ) that are distributed around user  750 . Further description of alignment of a user&#39;s face with respect to the optical sensors can be found below with respect to  FIGS. 9A-9AE  and  FIGS. 11A-11O   
       FIGS. 8A-8C  is a flow diagram illustrating a method for providing an instructional tutorial for enrolling a biometric feature on an electronic device in accordance with some examples. Method  800  is performed at a device (e.g.,  100 ,  300 ,  500 ,  700 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric features by the one or more biometric sensors. Some operations in method  2000  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  800  provides an intuitive way for providing an instructional tutorial for enrolling a biometric feature on an electronic device. The method reduces the cognitive burden on a user for enrolling a biometric feature on the device, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to enroll a biometric feature faster and more efficiently conserves power and increases the time between battery charges. 
     The device displays ( 802 ), on the display, a first user interface (e.g., face authentication set-up interface  712 ). While displaying the first user interface, the device detects ( 806 ) the occurrence of a condition that corresponds to introduction of a biometric enrollment process for enrolling a biometric feature (e.g., a face, finger, eye, voice, etc.). In some examples, the occurrence of a condition is an input that corresponds to a request to initiate the biometric enrollment process, such as finishing a prior stage of a device setup user interface process or selecting a biometric enrollment option in a settings user interface. In some examples, the biometric feature is used for authentication at the device. 
     In response to detecting the occurrence of the condition that corresponds to introduction of the biometric enrollment process, the device displays ( 808 ) a biometric enrollment introduction interface (e.g., face authentication tutorial interface  732 ). Displaying the biometric enrollment introduction interface includes concurrently displaying ( 810 ) a representation of a simulation of the biometric feature (e.g.,  720 , an animation of a biometric feature such as an animated face/head or a video of a biometric feature) and a simulated progress indicator (e.g., instructional progress meter  734 , a displayed element that indicates progress of enrollment). In some examples, the simulated progress indicator is located proximate to the representation of the simulation of the biometric feature. In some examples, the simulated progress indicator includes a plurality of progress elements (e.g., progress elements  734   a ,  734   b , and  734   c ) that are, optionally, distributed around the simulation of the biometric feature, such as a set of tick marks that extend (e.g., radially extend) outward from the simulation of the biometric feature and form an elliptical shape such as a circle. 
     In some examples, the representation of the simulation of the biometric feature is a representation ( 812 ) of a simulation of at least a portion of a face (e.g.,  720 ). In some examples, the representation is a representation of a simulation of a portion of a face. In some examples, the representation is a representation of a simulation of a face in its entirety. In some examples, the simulation of the biometric feature is a representation of a generic face such as a line drawing that includes eyes, nose, and a mouth. In some examples, the representation of a simulation of the biometric feature is a three-dimensional representation ( 814 ). For example, the representation of a simulation of the biometric feature is a three-dimensional rendered object. Alternatively, the instructional animation is optionally a 2D animation instead. 
     In some examples, the representation of the simulation of the biometric feature is a line drawing ( 816 ) with lines at different simulated z-height (e.g., a 3-D representation of  720 ). For example, when the line drawing of the face is tilted in different directions, the lines at different simulated z-heights appear to move relative to one another based on a simulated parallax effect. In some examples, the biometric enrollment introduction interface includes ( 820 ) an orientation guide (e.g., orientation guide  736 , a curved line that curves backward in a simulated z direction, as described in greater detail below with reference to method  1200 ) that is overlaid on the representation of the simulated biometric feature (e.g.,  720 ) and tilts in different directions as the representation of the simulated biometric feature tilts in different directions. 
     While displaying the biometric enrollment introduction interface, the device displays ( 824 ) an instructional animation (e.g., movement of  720  and advancement of instructional progress indicator  734  shown in  FIGS. 7H-7L ) that includes displaying movement (e.g., tilt and/or rotation) of the representation of the simulation of the biometric feature and incremental advancement of the progress indicator (e.g., progress elements of the progress indicator change color and/or shape in response to display of movement of the representation of the simulation of the biometric feature). Displaying an instructional animation that includes movement of the representation of the simulation of the biometric feature and incremental advancement of the simulated progress indicator illustrates, in advance, proper user inputs required for a subsequent biometric enrollment process (e.g., method  1200  and/or  1400 ) and therefore helps the user intuitively recognize how to quickly and properly enroll their biometric features, reducing the duration for which the device needs to display biometric enrollment interfaces (e.g.,  756 ) during this process and reducing the number of user inputs performed at those interfaces. Reducing the number of inputs and amount of time needed to perform the enrollment operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device displays ( 826 ) movement tilting the simulation of the biometric feature relative to a plane of the display of the device. For example, movement of the representation of the simulation includes rotation of the representation of the simulation along an axis normal to plane of the display of the device. In some examples, tilting relative to biometric sensor and/or the field of view of the sensor defines the plane of the display. In another example, the device displays ( 828 ) movement rotating the representation of the simulation of the biometric feature about a first axis (e.g., an axis normal to display  700 ) and rotating the representation of the simulation of the biometric feature about a second axis (e.g., an axis in the plane of display  700 ) different than the first axis. In some examples, the first axis is a vertical axis such that movement of the representation is from left to right and/or right to left. In some examples, the first axis is normal to the second axis. For example, the second axis is optionally a horizontal axis such that movement of the representation is downward and/or upward. In some examples, the first axis is any axis other than an axis normal to the display of the device (e.g., the representation rotates in any direction), and second axis is the axis normal to the display of the device. In this example, the simulated head optionally moves in a circular pattern around the second axis. Displaying movement tilting the simulation of the biometric feature relative to a plane of the display illustrates, in advance, proper user inputs required for a subsequent biometric enrollment process (e.g., method  1200  and/or  1400 ) and therefore helps the user intuitively recognize how to quickly and properly enroll their biometric features, reducing the duration for which the device needs to display biometric enrollment interfaces (e.g.,  756 ) during this process and reducing the number of user inputs performed at those interfaces. Reducing the number of inputs and amount of time needed to perform the enrollment operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, when displaying the instructional animation, the device optionally displays ( 830 ) the representation of the simulation of the biometric feature in a first position so as to reveal a first portion of the representation (e.g., a first side of  720 ) and not a second portion of the representation (e.g., a second, different side of  720 ). Subsequently, the device optionally displays the representation of the simulation of the biometric feature in a second position different than the first position so as to reveal the second portion of the representation and not the first portion of the representation. In the example that the biometric feature is a face, the simulated face optionally tilts in a first direction to reveal a first portion of the simulated face and then tilts in a second direction to reveal a second portion of the simulated face. Displaying the simulated biometric feature in a first orientation and subsequently displaying the simulated biometric feature in a second, different orientation illustrates, in advance, proper user inputs required for a subsequent biometric enrollment process (e.g., method  1200  and/or  1400 ) and therefore helps the user intuitively recognize how to quickly and properly enroll their biometric features, reducing the duration for which the device needs to display biometric enrollment interfaces (e.g.,  756 ) during this process and reducing the number of user inputs performed at those interfaces. Reducing the number of inputs and amount of time needed to perform the enrollment operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device displays the simulated progress indicator (e.g.,  734 ) surrounding the representation of the simulation of the biometric feature (e.g.,  720 ). For example, the simulated progress indicator is displayed such that the simulated progress indicator surrounds (or substantially surrounds) a portion or all of the representation of simulation of the biometric feature. In some examples, the simulated progress indicator is centered around the representation of the biometric feature of the user. In some examples, displaying the simulated progress indicator includes displaying ( 832 ) a plurality of progress elements (e.g., dots, circles, or line segments such as progress ticks  734   a ,  734   b , and  734   c ) proximate the representation of the simulation of the biometric feature (e.g., face graphic  720 ). In some examples, progress elements are equidistant from the representation and/or radially extend outward from the representation. In some examples, the progress elements are arranged in a circular, square, rectangular, or elliptical pattern. 
     In some examples, when displaying incremental advancement of the simulated progress indicator, the device transitions ( 834 ) one or more of the plurality of progress elements from a first state to a second state different than the first state. For example, in the first state, the progress elements are, optionally, of a first color and/or a first length, and in the second state, the progress elements are, optionally, of a second color different than the first color and/or a second length different than the first length. In some examples, progress elements optionally change in appearance in other manners as well. For example, the progress elements optionally change in line thickness, number, pattern, etc. Changing the display of portions of the simulated progress indicator allows the user to recognize that the changes in orientation of the simulated biometric feature illustrated in the instructional animation are required to properly enroll his/or her biometric features. This helps illustrate, in advance, proper user inputs required for a subsequent biometric enrollment process (e.g., method  1200  and/or  1400 ), reducing the duration for which the device needs to display biometric enrollment interfaces (e.g.,  756 ) during this process and reducing the number of user inputs performed at those interfaces. Reducing the number of inputs and amount of time needed to perform the enrollment operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the representation of the simulation of the biometric feature is a line drawing ( 836 ) that includes at least a portion (e.g., some or all) of a glyph (e.g., success-state progress meter  744 ) that is used to indicate successful biometric enrollment. In some examples, one or more progress elements of the simulated progress indicator are all updated to a second state (e.g., green and lengthened, or the state of meter portion  738  in  FIG. 7J ) and are not modified thereafter. In some examples, when each of the progress elements has been updated to the second state, the simulated progress indicator transitions to a success state (e.g., success-state progress meter  744 ). In some examples, transitioning the simulated progress indicator to the success state includes transitioning the simulated progress indicator to a solid circle surrounding the representation of simulation of biometric feature. 
     After displaying at least a portion of the instructional animation, the device detects ( 838 ) the occurrence of a condition that corresponds to initiation of the biometric enrollment process. In some examples, the condition that corresponds to initiation of the biometric enrollment process includes ( 840 ) a selection of an affordance to initiate the biometric enrollment process. For example, the condition is an input (e.g., user input at contact area  748 ) that corresponds to a request to “start enrollment” such as a tap on a “start enrollment” or “next” affordance (e.g., start affordance  746 ), optionally followed by aligning a biometric feature of the user with the one or more biometric sensors. A more detailed description of the biometric enrollment process is described in greater detail herein with reference to method  900 . In some examples, the electronic device provides a tactile and/or auditory output in response to selection of the affordance. 
     In response ( 842 ) to detecting the occurrence of the condition that corresponds to initiation of the biometric enrollment process, the device displays ( 844 ), at a location that was previously occupied by the representation of the simulation of the biometric feature in the biometric enrollment introduction interface (e.g., face authentication tutorial interface  732 ), a representation of the biometric feature of the user (e.g., user image  750 , a face of the user, a finger of the user, an eye of the user, a hand of the user) as determined by the one or more biometric sensors of the device. In some examples, the device optionally displays an enrollment progress user interface (e.g.,  756 ) after the representation of the biometric feature of the user (e.g.,  750 ,  760 ) has been aligned with the one or more biometric sensors (e.g.,  703 ) 
     In some examples, the representation is a representation ( 846 ) of a portion of the user&#39;s face (e.g., a portion of user image  750 ). In some examples, the representation is a representation of the user&#39;s face in its entirety. In some examples, the representation of the biometric feature of the user is a representation of the user that is specific to the user. For example, the representation of the user is images of the user&#39;s face or a wireframe that matches contours of the user&#39;s face. 
     In some examples, the biometric enrollment user interface includes ( 848 ) the orientation guide (e.g., orientation guide  736 , orientation guide  762 ) overlaid on the representation of the biometric feature (e.g., user image  750 ). The orientation guide optionally tilts as the biometric feature tilts in different directions. Displaying an orientation guide that moves as along with the user&#39;s biometric feature provides the user with feedback about the orientation of his or her biometric features relative to the biometric sensors of the device in three-dimensional space, enabling the user to place his or her biometric features in proper orientations more quickly during a subsequent enrollment process (e.g., method  1200  and/or method  1400 ). Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the representation of the biometric feature (e.g.,  750 ) of the user is based on ( 850 ) image data captured by the one or more cameras (e.g.,  703 ) of the electronic device. For example, the representation of the biometric feature of the user is, optionally, successive images of the user captured by the one or more cameras (e.g.,  703 ), or a wireframe that is based on movement of the user&#39;s features in a field of view of the one or more cameras. In some examples, the representation of the biometric feature changes ( 852 ) as the orientation of the biometric feature relative to the one or more biometric sensors changes. Updating the orientation of the displayed representation of the biometric feature provides the user with feedback about the orientation of his or her biometric features relative to the biometric sensors of the device, enabling the user to place his or her biometric features in a proper orientation more quickly during a subsequent enrollment process (e.g., method  1200  and/or method  1400 ). Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In response to detecting the occurrence of a condition that corresponds to initiation of the biometric enrollment process, the device also displays ( 854 ) a progress indicator (e.g.,  756 ) that corresponds to the simulated progress indicator (e.g., a progress indicator that has some or all of the features of the progress indicator displayed surrounding the simulation of the biometric feature such as a plurality of progress elements that are distributed around a representation of the biometric feature of the user). In some examples, displaying the progress indicator includes maintaining ( 856 ) the display of the simulated progress indicator. For example, the simulated progress indicator is returned to an initial state (e.g., the state of progress elements  734   a ,  734   b , and  734   c  in  FIG. 7H ) and used to show incremental enrollment progress of the user in a same or similar manner used to show incremental enrollment progress of the simulated biometric feature. Displaying an enrollment progress indicator that corresponds (e.g., is similar) to the simulated progress indicator allows the user to quickly associate changes in orientation of the simulated biometric feature and corresponding advancement of the simulated progress indicator illustrated during the instructional animation with the proper inputs required during a subsequent enrollment process (e.g., method  1200  and/or  1400 ). This in turn enables the user to more quickly complete the enrollment process, reducing the duration for which the device needs to display biometric enrollment interfaces (e.g.,  756 ) during this process and reducing the number of user inputs performed at those interfaces. Reducing the number of inputs and amount of time needed to perform the enrollment operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device displays ( 858 ) the progress indicator (e.g.,  758 ) surrounding the representation of the biometric feature of the user (e.g.,  760 ). For example, the progress indicator optionally has some or all of the features of the progress indicator that is displayed surrounding the simulation of the biometric feature. These features optionally include a plurality of progress elements (e.g.,  758   a ,  758   b ,  758   c ) that are distributed around a representation of the biometric feature of the user. For example, the progress indicator is displayed such that the progress indicator surrounds (or substantially surrounds) a portion or all of the representation of the biometric feature of the user. In some examples, the progress indicator is centered around the representation of the biometric feature of the user. 
     In some examples, in response to detecting the occurrence of the condition that corresponds to initiation of the biometric enrollment process, the device displays ( 860 ) a positioning element (e.g., positioning element  752 ) on the display of the electronic device. In some examples, the positioning element is displayed to emphasize a predetermined portion of the display of the electronic device (e.g.,  756 ,  758 ). In some examples, the positioning element indicates where a user should position the representation of the biometric feature of the user (e.g.,  750 ) for subsequent biometric feature enrollment. In some examples, the positioning element is an object visually at least partially partitioning first and second portions of the display (e.g., display portion  756  and display portion  758 ). The positioning element is a shape, such a square in some examples, and is optionally segmented. Displaying a positioning element that frames a particular portion of the digital viewfinder allows the user to quickly recognize whether the position and/or orientation of his or her biometric features within the biometric sensor&#39;s field of view is optimal for a subsequent biometric enrollment process (e.g., method  1200  and/or  1400 ), enabling the user to place his or her biometric features in a proper orientation more quickly. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     Note that details of the processes described above with respect to method  800  (e.g.,  FIGS. 8A-C ) are also applicable in an analogous manner to the methods described below. For example, method  800  optionally includes one or more of the characteristics of the various methods described below with reference to methods  1000 ,  1200 ,  1400 ,  1600 ,  1800 ,  2000 ,  2200 ,  2500 , and  2700 . For another example, the orientation guide described in method  1200  can be applied with respect to the instructional animation displayed on face authentication tutorial interface (e.g.,  732 ). For another example, one or more aspects of biometric enrollment described in method  1200  can be applied with respect to the enrollment interface (e.g.,  756 ). For another example, one or more aspects of hints described in method  1400  can be applied to display of the face authentication tutorial interface (e.g.,  732 ). 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 8A-8C  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, displaying operation  802 , detecting operation  806 , displaying operation  810 , displaying operation  824 , detecting operation  838 , displaying operation  844 , and displaying operation  854  are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 9A-9AE  illustrate exemplary user interfaces for instructional tutorial for enrolling a biometric feature on an electronic device (e.g., device  100 , device  300 , device  500 , or device  700 ), in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIG. 10 . 
       FIG. 9A  illustrates an electronic device  900  (e.g., portable multifunction device  100 , device  300 , device  500 , or device  700 ). In the exemplary example illustrated in  FIGS. 9A-9AE  electronic device  900  is a smartphone. In other examples, electronic device  900  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  900  has a display  901 , one or more input devices (e.g., touchscreen of display  901 , a button, a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  903 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  903  are the one or more biometric sensors  703 . In some examples, the device further includes a light-emitting device (e.g., light projector). such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     As illustrated in  FIG. 9A , device  900  displays a face authentication introduction interface  905 . In some examples, face authentication introduction interface  905  is similar to the face authentication tutorial interface  732  described above in connection with  FIG. 7S . By way of example, face authentication introduction interface  905  includes face graphic  902 , which is, optionally, the same as or similar to glyph  720 , described above with respect to face authentication tutorial interface  732 . Additionally or alternatively, device  900  optionally also display success-state instructional progress meter  907 , which is, optionally, the same or similar to success-state instructional progress meter  744  in  FIG. 7P-7Q . Face authentication introduction interface  905  also includes a start button  904  (e.g., a start affordance). As shown in  FIG. 9A , device  900  detects activation (e.g., selection) of start affordance  904 . For example, activation is, optionally, a user input at contact area  906  on start affordance  904 . This user input will, in some circumstances, correspond to a request to begin face authentication set-up (e.g., start face enrollment). 
     In some examples, in response to detecting user selection of start button  904 , device  900  displays face alignment interface  908  as shown in  FIG. 9B . Face alignment interface  908  includes positioning element  910 , which is a framing circle or brackets that, in some examples, indicates an alignment boundary. In some examples, the positioning element  910  identifies an inner display portion  912  and an outer display portion  912 . In some examples, the electronic device determines a biometric feature of a user is properly aligned when substantially positioned in the inner display portion  912  in a predetermined manner. In some examples, positioning element  910  partitions inner display portion  912  from outer display portion  914 . In general, if the user&#39;s face is positioned relative to biometric sensor  903  such that a portion of the image of the user appears in outer display portion  914 , the user&#39;s face will, in some circumstances, not be properly aligned with the cameras. As such, face alignment interface  908  also includes a text prompt  916  instructing the user to position his or her face inside of positioning element  910  (e.g., within inner display portion  812 ). 
     With reference to  FIG. 9C , in some examples, during the alignment process, a user positions the electronic device  900  substantially in front of the user&#39;s face  917 . In some examples, the user holds device  900  at approximately a same height as his or her face, such that the face is in the field of view of the biometric sensor  903 . 
     As illustrated in  FIG. 9D , once the user has initiated alignment process, the device displays a face alignment interface  908  (recall that the user optionally initiates the enrollment process by activating an affordance  904 ). Face alignment interface  908  includes a digital viewfinder showing a preview of image data captured by biometric sensor  903 . In some examples, the preview of image data is a live preview that continuously updates (e.g., changes over time) as the field of view of these cameras changes (e.g., if device  900  is moved or if the user moves closer/farther away from the cameras). The digital viewfinder includes user facial image  918 , as well as positioning element  910  superimposed on the field of view of the cameras. As described above, positioning element  910  partitions inner display portion  912  from surrounding outer display portion  914 . To provide further visual separation between inner display portion  912  (where user facial image  918  is to be positioned) and outer display portion  914 , device  900  visually obscures (e.g., shades, darkens or blurs) outer display portion  914 , as shown in  FIG. 9D . 
     In general, proper enrollment of a user&#39;s facial features for authentication requires that the user&#39;s face be positioned in a predetermined manner and/or within a predetermined range of distances from the cameras of device  900 . In some examples, alignment of a user&#39;s face with the cameras of device  900  requires the user to be neither too close nor too far away from the device. Thus, if the electronic device  900  determines that the face of the user is too close or too far, the electronic device displays text prompt  920  in the face alignment interface  908  instructing the user to position their face an acceptable distance (e.g., 20-40 mm) from device  900 . In the example of  FIG. 9D , device  900  detects that the user&#39;s face is too far away from the cameras on the device (e.g., user facial image  918  is within positioning element  910 , but does not substantially fill inner display portion  912 ). In some examples, the electronic device prompts the user to move his or her face closer to the device. In some examples, the device generates one or more outputs, such as audio output  922  (e.g., a series of beeps or other audio output) and tactile output  924  (e.g., a series of vibrations or other tactile output) to notify the user of improper alignment. In some examples, audio output  922  and/or tactile output  924  have a magnitude and repetition rate (e.g., frequency) that changes based on the distance between device  900  and the user&#39;s face. For example, the output frequency and/or magnitude optionally increases as the user&#39;s face moves closer to the acceptable range of distances (e.g., 20-40 mm) from the device. Conversely, the output&#39;s frequency and/or magnitude optionally decrease as the user&#39;s face moves further away from the acceptable range of distances. In this case, device  900  continuously changes (e.g., updates) the frequency and/or magnitude of audio output  922  and/or tactile output  924  as it detects changes in distance between the user&#39;s face and biometric sensor  903 . In some examples, device  900  provides these outputs as long as the user&#39;s face is outside the acceptable range of distances from the device. In some examples, audio output  922  and tactile output  924  is accompanied by a corresponding visual output on display  700 . These ongoing audio, tactile, and/or visual outputs optionally provides intuitive hints as to how a user is to correctly align his or her face with the cameras, reducing the time required to perform successful facial alignment. 
       FIG. 9E  illustrates face alignment interface  908  in the case where the user&#39;s face is positioned too close to device  900  (e.g., a substantial portion of user facial image  918  falls within outer display portion  914 ). In this case, alignment interface  908  also includes text prompt  920 , which instructs the user to position his or her face at an acceptable distance from device  900 . In some examples, the electronic device instructs the user to move his or her face closer to the device. As described above in connection with  FIG. 9D , device  900  optionally generates an ongoing audio output  922  and/or tactile output  924  in response to detecting that the user&#39;s face is too close to the camera(s). In particular, device  900  changes the frequency and/or magnitude of these outputs as it detects changes in distance between the user&#39;s face and the cameras. 
       FIG. 9F  illustrates face alignment interface  908  in the case that user&#39;s face is positioned at an acceptable distance from device  900 , but is out of frame (e.g., too far to the right or left). For example, face  918  is, optionally, positioned such that a substantial portion of the face  918  lies outside of positioning element  910  within outer display portion  914 . In this case, device  900  optionally displays text prompt  926  on alignment interface  908 , instructing the user to position his or her face within positioning element  910  (e.g., such that user image  918  is displayed within inner display area  912 ). 
     With reference to  FIGS. 9G-9L , in some examples, the electronic device  900  displays face alignment interface  908  in response to determining that a user&#39;s face is positioned outside a range of predetermined angles relative to the electronic device. As shown in  FIG. 9G , the electronic device  900  is positioned at a low angle relative to the electronic device (e.g., the electronic device is aligned with a chin of the user) such that the electronic device cannot properly obtain (e.g., capture biometric data). With reference to  FIG. 9H , in response to determining that the electronic device  900  is outside the range of predetermined angles, the electronic device  900  blurs at least a portion of face alignment interface  908 , such as the inner display portion  912  and outer display portion  914 . In some examples, the electronic device further outputs a prompt  986  instructing the user to position his or her face within positioning element  910  (e.g., such that user image  918  is displayed within inner display area  912  and at the proper angle). In  FIGS. 9I and 9K , the user raises the device  900  until the electronic device is within the predetermined range of angles. As the user raises the electronic device, with reference to  FIGS. 9J and 9K , the electronic device  900  gradually decreases the blur of displayed elements. In this manner, the electronic device indicates to the user that the angle of the electronic device relative to the user is approaching the acceptable range of angles. In some examples, the electronic device is too high relative to the user such that the electronic device is not within the predetermined range of angles. Similarly to the described example, the electronic device optionally decreases or increases blur of displayed objects as the electronic device is moved relative to the user. 
     In some examples, if the device detects that an alignment error persists for a predetermined amount of time, device  900  optionally displays accessibility options affordance  928  on face alignment interface  908 , as shown in  FIG. 9G . For example, device  900  optionally displays accessibility options affordance  928  if it does not detect a user face at an acceptable distance from the device and/or within the positioning element at a predetermined time after starting alignment (e.g., after start button  904  is selected). In some examples, the predetermined amount of time is, optionally, 10 seconds, 15 seconds, 30 seconds, or any other suitable amount of time. Similarly, device  900  optionally displays accessibility options affordance after a certain number of enrollment attempts have failed. As discussed in more detail below, device  900  optionally displays additional options or hints and/or initiate alternative facial enrollment processes in response to detecting selection of accessibility options affordance  928 . In some examples, activation of accessibility options affordance  928  enables the user to proceed with biometric enrollment without first correcting the alignment error. 
     In general, the quality of facial feature enrollment for the face authentication methods described herein at least partially depends on the lighting conditions under which the user&#39;s facial data is captured. For example, strong backlighting or direct exposure on the user&#39;s face will, in some circumstances, adversely affect the quality of enrollment. Turning now to  FIG. 9H , in response to detecting adverse lighting conditions, device  900  optionally displays text prompt  930  on alignment interface  908 , which indicates adverse lighting to the user. Text prompt  930  is, optionally, accompanied by an audio, visual and/or tactile output  932 . Output  932  is, optionally, the same as output  922  and/or  924  described in connection with the alignment errors discussed above. In some examples, outputs are error-specific; output  932  is, optionally, therefore be a different audio, visual, and/or tactile output than outputs  922  and  924 . 
     In general, the quality of facial feature enrollment also partially depends on the angle at which the user&#39;s face is orientated relative to one or more cameras of device  900  (e.g., biometric sensor  903 ). In particular, one or more optical sensors of device  900  must be able to capture image data of the user&#39;s face at a particular angle or within a predetermined range of angles. Even provided that the user&#39;s face is within the acceptable range of distances described above, face authentication enrollment can be adversely affected if device  900  is positioned to high above or too far below the user&#39;s face. Thus, in some examples, device  900  requires the user&#39;s face to be positioned within a predetermined range of angles relative to one or more of its cameras when detecting successful alignment conditions. 
     In some examples, device  900  blurs the image data displayed in the digital viewfinder of alignment interface  808  in response to detecting that the user&#39;s face is outside of this predetermined range of angles relative to biometric sensor  903 . In some examples, the amount of blurring optionally depends on the difference between the detected angle of elevation of the user&#39;s face relative to the camera and one or more threshold angles that bound the predetermined angle range. For example, device  900  blurs the preview image to a greater extent the higher or lower device  900  is positioned relative to the face of the user. If device  900  detects a change in the angle of elevation bringing its cameras into closer alignment with the user&#39;s face, it optionally lessens the amount of blurring as the angle of elevation changes (e.g., in a continuous gradient). In some examples, the preview image is not blurred if the angle of elevation between device  900  and the user&#39;s face is actively changing (e.g., the user is moving device  900  relative to his or her face). Blurring is, optionally, delayed until device  900  determines that the angle between the user&#39;s face and one or more of its cameras has been outside the predetermined angle range for a set period of time (e.g., 1 second, 2 seconds, 5 seconds, or any suitable time period). In some examples, only a portion of the preview image (e.g., outer display portion  914 ) is blurred, while the entire preview image is, optionally, blurred in other examples. Blurring the preview image in this manner optionally prompts the user to more quickly position device  900  at a desirable angle relative to his or her face, reducing the amount of time spent during the alignment process. In some examples, device  900  optionally issues generates a tactile and/or output to inform the user that his or her face is positioned at a suitable angle relative to biometric sensor  903 . 
     In  FIG. 9N , the user&#39;s face is properly positioned relative to biometric sensor  903 . In this case, face  918  is displayed substantially within alignment element  910  and inner display portion  912 . As shown in  FIG. 9N , face  918  also occupies a substantial portion of inner display portion  912 , indicating that the user&#39;s face is within the threshold range of distances from device  900 . In response to detecting a face that meets the above-described alignment criteria, device  900  issues audio output  934  and tactile output  936  to indicate successful alignment of the user&#39;s face with the cameras. In general, outputs  934  and  936  are different from outputs  922 ,  924 , and  932 , which are issued in response to detecting alignment errors. In some examples, device  900  captures and stores one or more images of the user&#39;s face upon successful alignment with the cameras. 
     In some examples, after detecting successful alignment, device  900  visually emphasizes inner display portion  912  in which face  918  is displayed. In the example of  FIG. 9P , device  900  further obscures the outer display portion  914  by blacking out or further blurring the image in the outer portion of the digital viewfinder preview while continuing to display the part of the digital viewfinder preview in inner display portion  914  (e.g., inside positioning element  910 ). In some examples, device  900  further visually emphasizes the contents of inner display portion  912  by enlarging or zooming in on the image within inner display portion  912 . 
     In some examples, the device further emphasizes the inner display portion  912  by changing the appearance of positioning element  910 . In particular, device  900  optionally changes the appearance of the alignment element by “rounding” the corners of the alignment element as shown in  FIG. 9P , and/or by merging the corners of the alignment element  910  into a circular positioning element  941  surrounding face  918 , as shown in  FIG. 9Q . 
     Turning now to the example of  FIG. 9R , in response to detecting that the user&#39;s face is oriented such that the above-referenced alignment criteria are met, device  900  initiates the face authentication enrollment process by displaying (e.g., replacing display of alignment interface  908  with) face enrollment interface  938 . In some examples, face enrollment interface  938  has similar or identical visual characteristics as face authentication enrollment interface  756  described above in connection with  FIG. 7S  or enrollment interface  1104  described below in connection with  FIG. 11A . In the example of  FIG. 9R , face enrollment interface  938  includes user facial image  939  displayed within positioning element  941 . In the example of  FIG. 9R , user facial image  939  is a live preview of image data captured by biometric sensor  903 . Face enrollment interface  938  also optionally includes enrollment progress meter  940  that surrounds user facial image  939  and positioning element  941 . As described above in connection with  FIG. 7S  and  FIGS. 11A-11H , enrollment progress meter  940  is composed of a set of progress elements (e.g.,  940   a ,  940   b , and  940   c ) that extend radially outward from user facial image  939  and, in some examples, enclose it in a circular pattern. Face enrollment interface  938  optionally includes orientation guide  942 . In some examples, the orientation guide includes a set of curved lines (e.g., crosshairs) that appear to extend out of the plane of display  901  in a virtual z-dimension, intersecting over the center of user facial image  939 . In some examples, orientation guide provides a sense of the three-dimensional orientation of the user&#39;s face even though face image  939  is two-dimensional. In this case, orientation guide  942  assists the user in the face enrollment process by making rotations and/or tilts of the user&#39;s head relative to device  900  more visually apparent. Face enrollment interface  938  also includes text prompt  944 , which optionally instructs the user to begin tilting their head, for instance, in a circle to perform enrollment. 
     Generally, the quality of enrollment is decreased if device  900  moves too much relative to the user&#39;s face once the enrollment process is initiated (e.g., the device should remain still while the user moves slowly rotates/tilts his or her face). In the example of  FIG. 9S , device  900  detects excess movement of its one or more cameras with respect to the user&#39;s face. This excess movement is, optionally, a significant change in orientation and/or position of the user&#39;s face relative to device  900  consistent with movement of the device itself, and that prevents reliable alignment and/or enrollment. In response, device  900  issues visual prompt  946  on enrollment interface  938  instructing the user to reduce movement of the device (e.g., prompting the user to hold the device still during the enrollment process). Device  900  optionally also concurrently generates visual and/or auditory output  948 . In some examples, movement of the device itself is measured by accelerometer  168  rather than biometric sensor  903 . Movement of the device is optionally also measured by a magnetometer, inertial measurement unit, or the like, of device  900 . 
     Successful enrollment typically requires that alignment of the user&#39;s face relative to the cameras on device  900  be maintained throughout the enrollment process. Thus, in some examples, device  900  optionally exits the face enrollment process if one more alignment errors are detected during enrollment. In some examples, if, during the enrollment process, the device  900  detects one or more alignment errors, the electronic device exits the enrollment process (e.g., ceases to display face enrollment interface  938 ), and initiates (e.g., transitions to) an alignment process in which, optionally, the device displays alignment interface  908 - 2 . In the examples of  FIGS. 9T-9U , alignment interface  908 - 2  and its components optionally has similar or identical visual characteristics as the initial alignment interface  908  described above with respect to  FIGS. 9B-9O . In the example of  FIG. 9T-U , device  900  has determined that the face of the user is out of the frame, and as a result, the device  900  displays user facial image  918 - 2  within inner display portion  912 - 2 , out of position compared to the successful alignment depicted in  FIG. 9O . In some examples, the device outputs an indication of the alignment error such as text prompt  950 , which indicates that user facial image  918 - 2  is not properly aligned within positioning element  910 . This example is merely illustrative. In some examples, the alignment error is, optionally, a failure to meet any of the other alignment criteria discussed above (e.g., distance from the device, angle of orientation, adverse lighting etc.). In such cases, text prompt  950  instruct the user move the device and/or their face into the acceptable range of distances, or correct the angle of orientation. In other some examples, the alignment error is, optionally, different from the criteria above such that a small change in alignment will not cause the device to exit the face enrollment process. In response to detecting the one or more alignment errors, the device visually de-emphasizes inner display portion  912 - 2  by revealing the portion of the image preview displayed in outer display portion  914 - 2  and displaying positioning element  910 - 2  as shown in  FIG. 9U . For example, device  900  lightens or unblurs the preview image in the outer display portion  914 - 2  to assist the user in re-aligning their face relative to biometric sensor  903 . In the example of  FIG. 9U , de-emphasizing inner display portion  912 - 2  reveals that a substantial portion of user facial image  918 - 2  is positioned outside of the positioning element  910 - 2  in outer display portion  914 - 2 . 
     In some examples, device  900  again detects that the user&#39;s face is properly aligned with biometric sensor  903 . In response, device  900  outputs audio output  934 - 2  and/or tactile output  936 - 2  indicating successful alignment. In some examples, audio output  934 - 2  and tactile output  934 - 6  have similar characteristics as audio output  934  and tactile output  936 , respectively, as described with reference to  FIG. 9O . In some examples, device  900  then resumes the enrollment process. For example, device  900  emphasizes inner portion  912 - 2  and facial image  918 - 2  in the manner discussed above with respect to inner display portion  912  and facial image  918 - 2  in  FIGS. 9P-9O . In some examples, device  900  resumes the enrollment process at the point in which the electronic device detected the alignment error (e.g., face enrollment interface  938  is displayed a second time with enrollment progress meter  940  advanced to the same state as when the alignment error was detected). 
     In some examples, if the device does not detect that proper alignment has been established (e.g., reestablished) within a predetermined time period, device  900  displays accessibility options affordance  928 - 2 , as shown in  FIG. 9V . In some examples, accessibility options provide an option to proceed with the enrollment process without all alignment conditions met, as described below. In some examples, the accessibility options provide an option to set up biometric (e.g., face) authentication with only partial enrollment (e.g., a scan of only a portion of the user&#39;s face). 
     In response to detecting activation (e.g., selection) of accessibility options button  928 - 2  (e.g., by tap gesture  952 ), the device displays accessibility enrollment interface  954 , illustrated in  FIG. 9W . One or more features of accessibility enrollment interface  954  has similar or identical visual characteristics to corresponding features of enrollment interface  938 . For example, in  FIG. 9W , face enrollment interface  954  includes user facial image  939 - 2  displayed within positioning element  941 - 2 . In some examples, user facial image  939 - 2  is a live preview of image data captured by biometric sensor  903 - 2 . Accessibility enrollment interface  954  also optionally includes enrollment progress meter  940 - 2  that surrounds user facial image  939 - 2  and positioning element  941 - 2 . As described above in connection with  FIG. 7S  and  FIGS. 11A-11H , enrollment progress meter  940 - 2  is composed of a set of progress elements (e.g.,  940 - 2   a ,  940 - 2   b , and  940 - 2   c ) that extend radially outward from user facial image  939 - 2  and, in some examples, enclose it in a circular pattern. Accessibility enrollment interface  954  optionally includes orientation guide  942 - 2 , In some examples, the orientation guide includes a set of curved lines (e.g., crosshairs) that appear to extend out of the plane of display  901  in a virtual z-dimension, intersecting over the center of user facial image  939 - 2 . Like face enrollment interface  938 , accessibility interface  954  optionally includes a text prompt (e.g., prompt  956 ) that provides written instructions for successfully completing the enrollment process. In some examples, accessibility enrollment interface  954  also includes completion affordance  956 , activation of which allows the user to exit the enrollment process and proceed to set up face authentication using only a partial scan of their facial features. In some examples, partial scans are, in some circumstances, helpful for a user having a condition that prohibits the user from tilting his or her head in all directions otherwise required for enrollment. 
     In response to activation (e.g., selection) of completion affordance  956  (e.g., by a user input  958  shown in  FIG. 9X ), the device displays face enrollment confirmation interface  960 , illustrated in  FIG. 9Y . Face enrollment confirmation interface includes facial image  939 - 3 , which, in the example of  FIG. 9Y , has similar visual characteristics to user facial image  939 - 2 . Facial image  939 - 3  is, optionally, surrounded by enrollment progress meter  962 , which is displayed in the successful authentication state described above in connection with  FIGS. 7P and 7Q . Face enrollment confirmation interface also includes partial scan enrollment affordance  964 , which allows the user to enroll the gathered facial data for use in device authentication. Face enrollment confirmation interface  960  also includes a back affordance  966 , which allows the user to navigate back to accessibility enrollment interface  954 . 
     As illustrated in  FIG. 9Z , the device detects a user input  968  corresponding to activation (e.g., selection) of back affordance  966 . In response to detecting the user input, device  900  displays (e.g., for a second time) accessibility enrollment interface  954 . While displaying accessibility enrollment interface  954 , device  900  detects movement (e.g., rotation and/or tilting) of the user&#39;s face relative to biometric sensor  903 . In the case of  FIG. 9AA , device  900  detects that the user&#39;s face has tilted in a particular direction (e.g., downwards and/or to the right towards meter portion  970 ). As described below in further detail with respect to  FIGS. 11B-11H , device  900  updates user facial image  939 - 2  based on the detected movement, and updates the position of orientation guide  942 - 2  to indicate that the user&#39;s head has tilted and/or rotated in three-dimensional space. In response to detecting movement of the user&#39;s face, device  900  captures image data of a portion of the user&#39;s face (e.g., the left side of the face) and concurrently changes the appearance of a corresponding portion (e.g., meter portion  970 ) of enrollment progress meter  940 - 2 . In some examples, device  900  elongates and or changes color of one or more progress elements in meter portion  970  to indicate that the portion of the user&#39;s face is currently being enrolled (as described in more detail with respect to  FIGS. 7I-7K and 11B-11H ). In some examples, device  900  maintains the display (e.g., does not change the appearance) of meter portion  972 , since meter portion  972  corresponds to a facial orientation that has not yet been enrolled. 
     As illustrated in  FIG. 9AB , in some examples, device  900  detects a change in orientation of the user&#39;s face relative to its one or more cameras (e.g., the user&#39;s face has tilted upwards) and updates user facial image  939 - 2  and orientation guide  942 - 2  accordingly. By way of example, because image data at the facial orientation corresponding to meter portion  972  has been successfully enrolled, device  900  transitions the state of the progress elements in meter portion  972  to an “enrolled” state as described in more detail below with respect to  FIGS. 11B-I  (e.g., by shading or changing the color and/or line width of the progress elements). As shown in  FIG. 9AB , device  900  again detects activation (e.g., selection) of done affordance  956  (e.g., by user input  958 - 2 ). 
     In response to detecting activation of completion affordance  956 , device  900  returns to displaying face enrollment confirmation interface  960  as shown in  FIG. 9AC . Since a portion of the user&#39;s face has been successfully enrolled, device  900  displays enrollment success indicator  974 , for instance, proximate to the user facial image  939 - 3 . In the example of  FIG. 9AC , enrollment success indicator  974  indicates orientations of the user&#39;s face that have been successfully enrolled. In some examples, the enrollment success indicator  974  is a circular bar. Accordingly, in some examples, enrollment success indicator  974  indicates (e.g., is located at) positions where enrollment progress meter transitioned to the success state during enrollment. 
     In some examples, because accessibility enrollment interface  960  allows the user to set up face authentication with only a partial enrollment of their facial features, partial scan enrollment affordance  964  is selectable. As shown in  FIG. 9AD , device  900  detects activation (e.g., selection) of partial scan enrollment affordance  964  (e.g., by user input  976 ). In response to detecting activation of partial scan enrollment affordance  964 , device  900  displays enrollment-complete interface  978 , illustrated in  FIG. 9AE  Enrollment completion interface  978  includes text prompt  980 , indicating to the user that the enrollment process is complete and face authentication has been securely set-up. Enrollment-complete interface  978  include optionally a generic face graphic  982  at a location that was previous occupied by user facial image  939 - 3 . In some examples, enrollment complete interface  978  also includes a done affordance, activation of which causes the electronic device to exit face authentication set-up. 
       FIG. 10  is a flow diagram illustrating a method for aligning a biometric feature on the display of an electronic device in accordance with some examples. Method  1000  is performed at a device (e.g.,  100 ,  300 ,  500 ,  900 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric features by the one or more biometric sensors. Some operations in method  2000  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  1000  provides an intuitive way for aligning a biometric feature on the display of an electronic device. The method reduces the cognitive burden on a user for enrolling a biometric feature on the device, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to enroll a biometric feature faster and more efficiently conserves power and increases the time between battery charges. 
     The device displays ( 1002 ), on the display, a first user interface (e.g.,  905 ). For example, the first user interface is, optionally, the enrollment introduction user interface as described above with respect to method  800 . 
     While displaying the first user interface, the device detects ( 1004 ) the occurrence of a condition that corresponds to initiating a biometric enrollment process for enrolling a respective type of biometric feature (e.g.,  917 ). For example, the occurrence of a condition is, optionally, an input (e.g.,  906  on start affordance  904 ) that corresponds to a request to “start enrollment.” 
     In response to detecting the occurrence of a condition that corresponds to initiating the biometric enrollment process (e.g., user input selecting initiation of enrollment), the device displays ( 1006 ), on the display, a digital viewfinder (e.g., display portions  912  and  914 ) including a preview of image data (e.g., user facial image  918 ) captured by the one or more cameras (e.g.,  903 ). In some examples, the preview of image data encompasses a first portion of a field of view of the one or more cameras (e.g., outer portion of field of view  914 ) and a second portion of the field of view of the one or more cameras (e.g., inner portion of field of view  912 ). In some examples, the second portion of the field of view (e.g.,  914 ) is ( 1008 ) a portion of the field of view that encloses (or partially encloses) the first portion of the field of view (e.g.,  912 ). In some examples, the inner portion of the field of view is, optionally, divided from outer portion by an alignment element (e.g., positioning element  910 ). In some examples, the preview of image data optionally changes over time as the content in the field of view of the one or more cameras (e.g.,  903 ) changes. Displaying a preview of the image captured by the biometric sensors provides the user with feedback about the position and orientation of his or her biometric features relative to the biometric sensors of the device, enabling the user to properly align his or her biometric features with the sensors more quickly and efficiently. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device concurrently displays ( 1010 ), with the preview of image data, an alignment element (e.g., positioning element  910 ) that indicates a portion of the preview (e.g.,  912 ) in which the user&#39;s face (e.g.,  918 ) should be placed in order to proceed with the biometric enrollment. For example, the alignment element is, optionally, a framing circle or framing brackets that are displayed in a central portion of the preview image (e.g.,  912 ) to prompt the user to move the device or their face into alignment with the central portion of the preview image. Displaying an alignment element that frames a particular portion of the digital viewfinder provides the user with feedback about the position of his or her biometric features relative to a portion of the biometric sensor&#39;s field of view corresponding to proper alignment of the biometric feature. This in turn enables the user to properly position his or her biometric features relative to the sensors more quickly and efficiently. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently 
     In some examples, after initiating the biometric enrollment process ( 1012 ), the device determines ( 1014 ) whether a biometric feature of the respective type (e.g.,  917 ) that meets alignment criteria has been detected in the field of view of the one or more cameras (e.g.,  903 ). Determining whether the user&#39;s biometric features are properly aligned with the biometric sensors improves the quality of subsequent biometric enrollment (e.g., according to methods  1200  and/or  1400 ) by ensuring that image data corresponding to particular portions and/or orientations of the biometric feature are captured during enrollment. This in turn improves the ability of the device to match a user&#39;s biometric feature with the captured data during biometric authentication at the device. Performing an optimized operation when a set of conditions has been met without requiring further user input user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in response ( 1016 ) to detecting the biometric feature of the respective type (e.g.,  917 ) that meets alignment criteria, the device outputs ( 1018 ) a tactile output of a first type (e.g.,  934 ,  936 ,  934 - 2 ,  936 - 2 , e.g., the tactile output is an output corresponding to successful alignment). Issuing a tactile output upon detecting that the biometric feature is properly aligned with the biometric sensors provides the user with feedback indicating successful alignment, which prompts the user to maintain the biometric feature in that alignment throughout a subsequent biometric enrollment process (e.g., methods  1200  and/or  1400 ). Providing improved tactile feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs during biometric enrollment and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in response ( 1016 ) to detecting the biometric feature of the respective type that meets alignment criteria, the device stores ( 1020 ) image data corresponding to the biometric feature (e.g.,  917 ). In some examples, on successful alignment, the device captures data associated with the biometric feature. Storing biometric (e.g., image) data in response to detecting successful alignment of the biometric feature allows the device to automatically capture data that be referenced during a subsequent biometric authorization attempt. Performing an optimized operation when a set of conditions has been met without requiring further user input user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the alignment criteria includes ( 1024 ) a requirement that at least a portion of the biometric feature (e.g.,  917 ) is within the first portion of the field of view (e.g., inner display portion  912 ,  912 - 2 ) of the one or more cameras. For example, in some examples, the electronic device determines whether the image data includes data corresponding to the biometric feature that satisfies the alignment criteria. In some examples, the alignment criteria include ( 1050 ) lighting conditions criteria. In some examples, alignment criteria require that lighting conditions of the electronic device are adequate for capturing image data during biometric feature enrollment, including a requirement that at least a first threshold amount of light is detected and/or that no more than a second threshold amount of light is detected (e.g., by  903 ). 
     In some examples, the alignment criteria include ( 1052 ) a requirement that a portion of the biometric feature (e.g., a portion of  917 ) is oriented relative to the electronic device in a predetermined manner. In examples where the biometric feature is a face of a user, the alignment criteria optionally includes a requirement that the user gaze is directed toward at least one of the one or more cameras (e.g.,  903 ) of the electronic device or the display (e.g.,  901 ) of the electronic device. In some examples, the requirement that a portion of the biometric feature (e.g., a portion of user facial image  918 ) is oriented relative to the electronic device in a predetermined manner is a requirement that the biometric feature (e.g.,  917 ) is positioned within a threshold angle (e.g., angle of elevation) relative to the one or more biometric sensors (e.g.,  903 ). In some examples, the alignment criteria require that the biometric feature (e.g.,  917 ) is positioned relative to the biometric sensors (e.g.,  903 ) in a predetermined manner such that the biometric sensors can capture biometric data corresponding to the biometric feature at a particular angle, or within a range of angles. In some examples, the device blurs the display of the electronic device (e.g., display portions  912  and/or  914 ), for instance, based on the degree to which the biometric feature (e.g.,  917 ) is outside of a predefined range of angles with respect to the one or more biometric sensors (e.g.,  903 ). 
     In some examples, the alignment criteria include ( 1042 ) a requirement that the biometric feature (e.g.,  917 ) is within a first threshold distance from the one or more biometric sensors (e.g.,  903 , e.g., the biometric feature is not too far from the biometric sensors) and a requirement that the biometric feature is not within a second threshold distance from the one or more biometric sensors (e.g., the biometric feature is not too close to the biometric sensors) ( 1026 ). 
     In some examples, while the biometric feature (e.g.,  917 ) is at a first distance from the electronic device that is not within the predetermined range of distances from the electronic device, the device detects ( 1044 ), by the one or more cameras (e.g.,  903 ), a change in distance of the biometric feature (e.g.,  917 ) from the first distance to a second distance from the electronic device that is not within the predetermined range of distances from the electronic device. In response to detecting the change in distance, the device generates ( 1046 ) an output (e.g., an audio, tactile, and/or visual outputs  922 ,  924 ) having a value of an output characteristic (e.g., a magnitude or amplitude, or a frequency or repetition rate) that varies based on a distance of the biometric feature from the predetermined range of distances. In some examples, the electronic device issues an ongoing audio output (e.g.,  924 , e.g., a series of beeps) having a frequency that increases as the distance between the biometric feature (e.g.,  917 ) and the electronic device approaches a target distance (or range of distances) from the electronic device. For example, the rate of beeping optionally increases. Conversely, the frequency of the audio output (e.g.,  922 ) optionally decreases as the distance between the biometric feature and the electronic moves further away from the target distance (or range of distances) from the electronic device. For example, the rate of beeping optionally decreases. In some examples, similar feedback is generated with tactile outputs (e.g., output  924 ) or visual outputs. Issuing an audio, tactile, and/or visual output that varies based on the distance between the biometric feature and the device provides ongoing feedback to the user about the position of his or her biometric features relative to a range of distances from the biometric sensors corresponding to proper alignment. This in turn reduces the amount of time alignment interfaces are displayed and reduces the number of user inputs that are required during the alignment process. Providing improved audio, tactile and/or visual feedback to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently 
     After initiating the biometric enrollment process, in accordance with a determination that a biometric feature of the respective type (e.g.,  917 ) that meets alignment criteria has been detected in the field of view of the one or more cameras (e.g.,  903 ) ( 1022 ), the device emphasizes ( 1028 ) the first portion of the field of view (e.g., inner display portion  912  in  FIG. 9J ) of the one or more cameras relative to the second portion of the field of view (e.g., outer display portion  914  in  FIG. 9J ) of the one or more cameras (e.g., darken, blur, and/or black out the second portion of the field of view without darkening, blurring, and/or blacking out the first portion of the field of view of the one or more cameras). For example, the alignment criteria include a requirement that a face of user (e.g.,  917 ) is aligned with the camera (e.g.,  903 ) in a predetermined alignment, or an eye of the user is aligned with the camera in a predetermined alignment. Providing a visual effect that emphasizes a portion of the display upon detecting successful alignment of the user&#39;s biometric features with the biometric sensors allows the user to quickly recognize that the current position of his or her biometric features is optimal for a subsequent biometric enrollment process (e.g., according to methods  1200  and/or  1400 ). Providing improved visual feedback when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device darkens ( 1030 ) a portion of the digital viewfinder that corresponds to the second portion of the field of view (e.g.,  914  in  FIG. 9J ) of the one or more cameras (e.g.,  903 ). Darkening in this manner includes dimming or lowering brightness of the portion of the digital viewfinder that corresponds to the second portion of the field of view. 
     In some examples, the device ceases to display ( 1032 ) the portion of the digital viewfinder that corresponds to the second portion of the field of view (e.g., second display portion  914 ) of the one or more cameras. For example, ceasing to display the portion of the viewfinder corresponding to the second portion of the field of view includes blacking out the second portion of the field of view and/or replacing the display of the second portion of the field of view with display of other content. 
     In some examples, the device enlarges ( 1034 ) display of the first portion of the field of view (e.g., inner display portion  912 ) of the one or more cameras on the display. In some examples, enlarging display of the first portion includes enlarging display of some or all of first the portion of the field of view. In some examples, enlarging display of the first portion of the field of view includes zooming in on the first portion of the field of view. In some examples, emphasizing the first portion of the field of view (e.g.,  912 ) of the one or more cameras relative to the second portion of the field of view (e.g.,  914 ) of the one or more cameras includes shrinking or hiding some or all of first portion. In some examples, the device shrinks the first portion prior to enlarging display of first portion and/or shrinks the first portion after enlarging display of the first portion (e.g., to provide a zoom in and zoom out effect). 
     In some examples, the device modifies ( 1036 ) the alignment element (e.g.,  910 ). For example, in some examples, modifying the alignment element includes removing the alignment element. In some examples, modifying the alignment element includes changing the shape and/or color of the alignment element (e.g., from  910  to  910 - 2   FIGS. 9J-9K ). For example, the device modifies ( 1038 ) a shape of the alignment element from a first shape to a second shape. In some examples, the first shape ( 1040 ) is substantially rectangular and the second shape is substantially circular. Alternatively, the first shape and/or second shape is, optionally, any other shape or portion of a shape. In some examples, a shape is, optionally, a segmented shape, such as a segmented rectangle (e.g., a rectangle that is missing a portion of one or more sides). 
     In some examples, after emphasizing the first portion of the field of view (e.g.,  912 ) of the one or more cameras relative to the second portion of the field of view (e.g.,  914 ) of the one or more cameras (e.g.,  903 ), the device detects ( 1054 ) that the biometric feature of the respective type that meets alignment criteria (e.g.,  917 ) is no longer detected in the field of view of the one or more cameras. In response to detecting that the biometric feature of the respective type that meets alignment criteria is no longer detected in the field of view of the one or more cameras, the device outputting an indication of an alignment error (e.g.,  950 ). For example, for correctable errors, the device identifies the error and prompts the user to correct the error. For uncorrectable errors, the device only identifies the error. Errors are identified by text and a tactile output (e.g.,  950 ,  924 ,  925 ). In some examples, errors are identified using auditory outputs, such as those provided for accessibility purposes. In some examples, the criteria for detecting that the biometric feature is no longer detected in the field of view of the one or more cameras is the same as the criteria for determining that the biometric feature meets the alignment criteria. In some examples the alignment criteria are different from the criteria for detecting that the biometric feature is no longer detected in the field of view of the one or more cameras (e.g., once the biometric feature is aligned with the one or more cameras, the biometric feature can be moved slightly out of alignment without the device exiting the biometric enrollment process and outputting an indication of an alignment error). Outputting an indication that the user&#39;s biometric feature is no longer aligned with the biometric sensor provides feedback allowing the user to quickly recognize that the position and/or orientation of his or her biometric feature has deviated from previously established alignment. This feedback prompts the user to quickly reposition his or her biometric feature to re-establish proper alignment with the biometric sensor, reducing amount of time that alignment user interfaces are displayed, reducing the number of inputs required at these alignment user interfaces, and improving the quality of biometric feature enrollment. Providing improved audio, tactile and/or visual feedback to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, outputting an indication of an alignment error includes outputting ( 1056 ) a tactile output of a second type (e.g.,  951 ). For example, the tactile output is an output corresponding to a loss of successful alignment. In some examples, tactile outputs are error-specific, and, in some examples, auditory output is additionally or alternatively provided. 
     In some examples, outputting the indication of the alignment error includes ( 1058 ) deemphasizing the first portion of the field of view of the one or more cameras (e.g.,  912 - 2 ) relative to the second portion of the field of view of the one or more cameras (e.g.,  914 - 2 ). For example, the device, optionally, lightens, unblurs, and/or reveals the second portion of the field of view relative to the first portion of the field of view of the one or more cameras. In some examples, the electronic device lightens and unblurs the second portion of the field of view to deemphasize the first portion relative to the second portion. In some examples, if the biometric feature (e.g.,  917 ) is successfully aligned after receiving the alignment error, the device resumes the biometric enrollment process from where the enrollment process was prior to outputting the indication of the alignment error (e.g., the enrollment progress up to the point when the alignment error was detected, is preserved). In some examples, a progress indicator (e.g.,  940 ) that indicated enrollment progress disappears when the indication of the alignment error is output, but is redisplayed (e.g.,  940 - 2 ) when the biometric feature is properly aligned with the one or more biometric sensors. In some cases, when the progress indicator is redisplayed it includes an indication of the progress made in enrolling the biometric feature prior to outputting the indication of the alignment error. Providing a visual effect that de-emphasizes a portion of the display upon detecting an alignment error allows the user to quickly recognize that the position and/or orientation of his or her biometric feature has deviated from previously established alignment. This feedback prompts the user to quickly reposition his or her biometric feature to re-establish proper alignment with the biometric sensor, which reducing amount of time that alignment user interfaces are displayed, reduces the number of inputs required at these alignment user interfaces, and improves the quality of subsequent biometric feature enrollment (e.g., according to methods  1200  and/or  1400 ). Providing improved visual feedback when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in accordance with ( 1062 ) a determination that the alignment error is an alignment error of a first type (e.g., the biometric feature is too far from or too close to the electronic device), the device outputs ( 1064 ) (e.g., displays) a prompt (e.g.,  920 ) to move the biometric feature to correct the alignment error of the first type. For example, the device prompts the user to move closer to or move further away from the electronic device, respectively. 
     In some examples, in accordance with a determination ( 1062 ) that the alignment error is an alignment error of a second type (e.g., the biometric feature is out of the first portion of the field of view), the device outputs ( 1064 ) (e.g., displays) a prompt (e.g.,  950 ) to move the biometric feature to correct the alignment error of the second type. For example, the device prompts the user to move the biometric feature into the first portion of the field of view. In this case, the device forgoes ( 1068 ) outputting a prompt (e.g.,  926 ) to move the biometric feature to correct the alignment error of the first type. In some examples, the second portion of the field of view (e.g.,  914 - 2 ) is modified (e.g., blurred) in response to determining that the alignment error is an alignment error of a second type. 
     For example, the alignment error of the first type is ( 1074 ) that a portion of the biometric feature (e.g., portion of  917  shown in  939 ,  918 - 2 ) is oriented outside of the first portion of the field of view (e.g.,  912 ,  912 - 2 ). In this case, the device outputs ( 1076 ) a prompt (e.g.,  950 ) to move the portion of the biometric feature into the first portion of the field of view to prompt the user to correct the alignment error of the first type. Providing a prompt with instructions on how to correct the alignment error provides feedback that allows the user to quickly recognize how to reposition his or her biometric features in order to re-establish proper alignment and proceed with the enrollment process. This in turn reduces the amount of time in which the device displays alignment interfaces and reduces the number of user inputs required at these alignment interfaces. Providing improved visual feedback when a set of conditions has been met enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In another example, the alignment error of the first type is ( 1078 ) that a distance between a portion of the biometric feature (e.g.,  917 ) and the one or more biometric sensors (e.g.,  903 ) is within a threshold distance (e.g., the biometric feature is too close to the one or more biometric sensors). In this case, the device outputs ( 1080 ) a prompt (e.g.,  920 ) to move the biometric feature away from the electronic device to prompt the user to correct the alignment error of the first type. 
     In another example, the alignment error of the first type is ( 1082 ) that a distance between a portion of the biometric feature (e.g.,  917 ) and the one or more biometric sensors (e.g.,  903 ) exceeds a threshold distance (e.g., the biometric feature is too far from the one or more biometric sensors). In this case, the device outputs ( 1084 ) a prompt (e.g.,  920 ) to move the biometric feature closer to the electronic device to prompt the user to correct the alignment error of the first type. 
     In another example, the alignment error of the first type is that an angle of the biometric feature (e.g.,  917 ) relative to the one or more biometric sensors (e.g.,  903 ) is outside of a predefined range of angles (e.g., angles of elevation) relative to the one or more biometric sensors. For example, the biometric feature is, in some circumstances, too high. In another example, the one or more biometric sensors is, in some circumstances, too low. In this case, the device outputs a prompt to move the biometric feature to adjust the angle (e.g., angle of elevation) of the biometric feature relative to the one or more biometric sensors. 
     In some examples, in accordance with a determination that the error condition of the first type persists for a threshold time period ( 1086 ), the device displays ( 1088 ) an accessibility interface (e.g.,  908 ) that enables the user to proceed with the biometric enrollment without correcting the error condition. For example, in some examples, the device enables a user to proceed with biometric enrollment without moving the biometric feature (e.g.,  917 ) relative to the device such that the error condition is corrected or without tilting the biometric feature to capture images of a different side of the biometric feature. In some examples, the device enables a user to proceed with biometric enrollment in this manner if the biometric feature is improperly aligned for a predetermined amount of time and/or in response to a predetermined number of failed requests. 
     In some examples, after outputting the alignment error, in accordance with a determination that a biometric feature of the respective type (e.g.,  917 ) that meets alignment criteria has been detected in the field of view of the one or more cameras (e.g.,  903 ), the device again emphasizes ( 1070 ) the first portion of the field of view (e.g.,  912 - 2 ) of the one or more cameras relative to the second portion of the field of view (e.g.,  914 - 2 ) of the one or more cameras. For example, optimally the device darkens, blurs, and/or blacks out the second portion of the field of view of the one or more cameras (e.g.,  914 - 2 ) without darkening, blurring, and/or blacking out the first portion of the field of view of the one or more cameras (e.g.,  912 - 2 ). 
     In some examples, after outputting the alignment error, and in accordance with a determination that a biometric feature of the respective type that meets alignment criteria (e.g.,  917 ) has been detected in the field of view of the one or more cameras (e.g.,  903 ), the device outputs ( 1072 ) a tactile output of the first type (e.g.,  936 ). In some examples, however, the device outputs a tactile output of a third type different than the first type and the second type. 
     In accordance with a determination that a biometric feature of the respective type (e.g.,  917 ) that meets alignment criteria has not been detected in the field of view of the one or more cameras (e.g., a face or eye of a user has not been detected in the predetermined alignment), the device maintains ( 1090 ) display of the digital viewfinder without emphasizing the first portion of the field of view (e.g.,  912 ,  912 - 2 ) of the one or more cameras relative to the second portion of the field (e.g.,  914 ,  914 - 2 ) of view of the one or more cameras (e.g.,  903 ). 
     In some examples, the device detects ( 1092 ) a change in orientation and/or position of the biometric feature (e.g.,  917 ) relative to the one or more biometric sensors (e.g.,  903 ). For example, the device detects, optionally, a change in position, a change in orientation, or both a change in orientation and position. 
     In some examples, in response to detecting ( 1094 ) the change in orientation and/or position of the biometric feature (e.g.,  917 ) relative to the one or more biometric sensors (e.g.,  903 ), and in accordance with a determination that device movement criteria have been met (e.g., the device is physically moving more than the threshold amount in a manner that prevents reliable alignment/enrollment), the device outputs ( 1096 ) a prompt (e.g.,  946 ,  948 , a visual, tactile or audible alert) to reduce movement of the electronic device. In some examples, the device detects reduced movement of the device and in response to detecting the reduced movement of the device ceases to output the prompt. In some examples, movement of the device is determined based on the one or more biometric sensors (e.g.,  903 ). For example, the change in orientation and/or position of the biometric feature relative to the one or more biometric sensors is consistent with movement of the device around the biometric feature rather than movement of the biometric feature in view of the one or more biometric sensors. In some examples, the movement of the device is determined based on one or more orientation sensors of the device, such as an accelerometer (e.g.,  168 ), a magnetometer, an inertial measurement unit, or the like, that are separate from the one or more biometric sensors. 
     In some examples, while the biometric feature (e.g.,  917 ) is within a first portion of a field of view (e.g.,  912 ) of the one or more biometric sensors (e.g.,  903 ) and is within a threshold distance of the one or more biometric sensors, and in accordance with a determination that the biometric feature is within of a predefined range of angles (e.g., angles of elevation relative to the one or more biometric sensors), the device displays an enrollment progress indicator (e.g.,  940 ) for enrollment of the biometric feature (e.g., as described in greater detail with reference to method  1200  and  FIGS. 11A-11E ). Displaying the enrollment progress indicator optionally includes first emphasizing the first portion of the field of view (e.g.,  912 ,  912 - 2 ) of the one or more cameras relative to the second portion of the field of view (e.g.,  914 ,  914 - 2 ) of the one or more cameras as described above. Displaying the progress indicator during enrollment in this manner encourages the user to look at the display of the electronic device during the enrollment to improve the ability to detect when gaze is directed at the display, and thus whether or not the user is paying attention to the device. Encouraging the user to look at the display of the electronic device enhances the operability of the device and makes the user-device interface more efficient (e.g., by ensuring that the gaze of the user is directed at the display and thereby ensuring that the biometric feature of the user is properly enrolled) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in accordance with a determination that the biometric feature (e.g.,  917 ) is outside of the predefined range of angles (e.g., angles of elevation relative to the one or more biometric sensors  903 ), the device obscures (e.g., blurs, darks, or desaturates) at least a portion of the preview of the image data (e.g., display portions  912 ,  912 - 2 ,  914  and/or  914 - 2 ). In some examples, the device delays obscuring the portion of the preview of the image data (e.g., for at least a predetermined time period such as 1 second, 2 seconds, or 5 seconds after detecting that the biometric feature is within the first portion of the field of view and within the threshold distance of the one or more biometric sensors) so that the portion of the preview of the image data is not obscured if the user is actively shifting the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  903 ). In some examples, the obscuring is delayed as long as the angle of the biometric feature is changing. In some examples, the obscuring is delayed until the angle of the biometric feature has been continuously outside of the predefined range of angles for at least the predetermined time period. In some examples, only a portion of the preview is obscured (e.g.,  912  or  914 ,  912 - 2  or  914 - 2 ). In some examples, all of the preview is obscured (e.g.,  912  and  914 ,  912 - 2  and  914 - 2 ). Obscuring the digital viewfinder when the biometric sensors are positioned too high above or too far below the user&#39;s biometric feature allows the user to quickly recognize that his or her biometric feature is out of alignment. This in turn prompts the user to change the angle of elevation between the device and his or her biometric feature until proper alignment is established. Providing improved visual feedback when a set of conditions has been met enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, while the portion of the preview of the image data (e.g.,  912  or  914 ) is obscured, the device detects a change in the angle of the biometric feature (e.g.,  917 ) with respect to the one or more biometric sensors (e.g.,  903 ). In response to detecting the change in the angle of the biometric feature with respect to the one or more biometric sensors, and in accordance with a determination that the change in angle moves the biometric feature closer to the predefined range of angles without moving the biometric feature into the predefined range of angles, the device reduces an amount of the obscuring of the portion of the preview of the image data (e.g.,  912  or  914 ,  912 - 2  or  914 - 2 ) while continuing to obscure the portion of the preview of the image data. In some examples, the amount by which the obscuring of the portion of the preview of the image data is reduced depends on an amount of the change in the angle of the biometric feature with respect to the one or more biometric sensors (e.g., the more the biometric feature moves toward the one or more biometric sensors, the greater the reduction in the amount of obscuring). In accordance with a determination that the change in angle moves the biometric feature into the predefined range of angles, the device ceases to obscure the portion of the preview of the image data. In some examples, when the change in angle of the biometric feature moves the biometric feature into the predefined range of angles, the device generates a tactile and/or audio output to inform the user that the angle of the biometric feature is within the predefined range of angles (e.g.,  934 ,  936 ). Reducing obscuration of the digital viewfinder as the user&#39;s biometric feature moves closer to the pre-defined angle range allows the user to quickly recognize a set of positions that correspond to successful alignment of the biometric feature. This in turn prompts the user to change the angle of elevation between the device and his or her biometric feature until proper alignment is established. Providing improved visual feedback when a set of conditions has been met enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in response to detecting the change in angle of the biometric feature (e.g.,  917 ) with respect to the one or more biometric sensors (e.g.,  903 ), and in accordance with a determination that the change in angle moves the biometric feature further away from the predefined range of angles, the device increases an amount of the obscuring of the portion of the preview of the image data (e.g.,  912  or  914 ,  912 - 2  or  914 - 2 ). In some examples, the amount by which the obscuring of the portion of the preview of the image data is increased depends on an amount of the change in the angle of the biometric feature with respect to the one or more biometric sensors (e.g., the more the biometric feature moves away the one or more biometric sensors, the greater the increase in the amount of obscuring). 
     In some examples, obscuring includes blurring the preview of the image data, and reducing the amount of the obscuring of the portion of the preview of the image data includes reducing an amount of blurring of the preview of the image data (e.g., by reducing a blur radius or other blur parameter). In some examples, increasing the amount of the obscuring of the portion of the preview of the image data includes increasing a blur radius or other blur parameter. 
     Note that details of the processes described above with respect to method  1000  (e.g.,  FIGS. 10A-10F ) are also applicable in an analogous manner to the methods described below. For example, method  1000  optionally includes one or more of the characteristics of the various methods described below with reference to methods  800 ,  1200 ,  1400 ,  1600 ,  1800 ,  2000 ,  2200 ,  2400 , and  2700 . For example, the enrollment process as described in method  1200  can be applied with respect to the face enrollment interface (e.g.,  954 ). For another example, hints as described in method  1400  can be applied with respect to the enrollment progress meter (e.g.,  940 ). For another example, accessibility features, as described in method  1400 , can be applied, in lieu of, or in combination with, the accessibility options (e.g.,  928 - 2 ). For brevity, these details are not repeated below. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 9A-9I  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, displaying operation  1002 , detecting operation  1004 , displaying operation  1006 , emphasizing operation  1028 , and maintaining operation  1090  are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
     Attention is now directed to  FIGS. 11A-11L , which illustrate exemplary user interfaces for registering a biometric feature on an electronic device (e.g., device  100 , device  300 , device  500 , device  700  or device  900 ), in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIG. 12 . 
       FIG. 11A  illustrates an electronic device  1100  (e.g., portable multifunction device  100 , device  300 , device  500 , device  700 , or device  900 ). In the exemplary example illustrated in  FIGS. 11A-11L , electronic device  1100  is a smartphone. In other examples, electronic device  1100  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  1100  has a display  1102 , one or more input devices (e.g., touchscreen of display  1102 , a button, a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  1103 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  1103  are the one or more biometric sensors  703 . In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     As illustrated in  FIG. 11A , device  1100  displays a face enrollment user interface  1104  on display  1102 . In some examples, face enrollment user interface  1104  is displayed after device  1100  detects successful alignment of the user&#39;s face relative its one or more cameras, as described above in connection with  FIGS. 9A-9AE  Face enrollment interface  1104  includes user facial image  1106 . In some examples, user facial image  1106  is an image of the user captured by one or more cameras on device  1100 . For example, user facial image  1106  optionally is live preview of the image data captured by the one or more cameras (e.g., a digital viewfinder) that updates continuously as the field of view of the camera and/or the field of view&#39;s contents change. In some examples, background content is removed such that only the user&#39;s face is visible in facial image  1106 . Face enrollment interface also optionally includes orientation guide  1108  that is superimposed (e.g., overlaid) on user facial image  1106 . As described above in connection with  FIGS. 7I-7K , orientation guide  1108  is, optionally, a set of curved lines that extend into a virtual z-dimension (e.g., along an axis normal to the plane of the display) and intersect over the center of user facial image  100 . Thus, the curved lines of orientation guide  1108  appear to bulge outwards relative to the plane of display  1102  to give a sense of the position of the user&#39;s head in three-dimensional space. 
     Face enrollment user interface  1104  also includes enrollment progress meter  1110 . Enrollment progress meter  1110  includes a set of display elements (e.g., progress elements  1110   a ,  1110   b , and  1110   c ) that are arranged around user facial image  1106  and orientation guide  1108 . In the example of  FIG. 11A , the progress elements are a set of lines that extend radially outward from user facial image  1106  arranged in a circular pattern. In some examples, progress elements  1110   a ,  1110   b ,  1110   c , etc. indicate an orientation of the user&#39;s face needed to enroll corresponding facial features. For example, progress elements in the upper portion of enrollment meter  1110  optionally move, fill in, elongate, and/or change color when the user&#39;s head is tilted upwards, which allows the one or more cameras on device  1100  to capture image data of the under-side of the user&#39;s face. This process is described in more detail below. In the example of  FIG. 9A , device  1100  displays progress elements in enrollment progress meter  1110  in an unenrolled state (e.g., the progress elements are greyed out). 
     Face enrollment interface  1104  also includes a text prompt  1112 , which instructs the user to move (e.g., rotate and/or tilt) their head in a circular motion during the enrollment process. In some examples, text prompt  1112  is optionally accompanied by tactile and/or auditory prompt depending on device settings and/or user selections. In some examples, device  1100  displays text prompt  1112  on enrollment interface  1104  through the facial enrollment process. 
     As illustrated in  FIG. 11B , device  1100  detects movement of the user&#39;s face relative to its one or more cameras. The movement of the user&#39;s face is, optionally, a rotating and/or tilting motion relative to the device  1100 . In response, device  1100  continually updates (e.g., displays movement of) user facial image  1106  to reflect the change in orientation of the user&#39;s face. In some examples, orientation guide  1108  tracks the movement (e.g., moves along with) user facial image  1106  to provide visually emphasize tilting and rotational movements of the user&#39;s face in three-dimensions. For example, the center (e.g., intersection) of orientation guide  1108  is, optionally, positioned at a central point on user facial image  1106  and move along with it. In some examples, device  1100  also adjusts the curvature of the lines comprising orientation guide  1108  to give the appearance of three-dimensional rotation (e.g., with respect to an axis normal to display  1100 ). In some examples, device  1100  emphasizes orientation guide  1108  while it is in motion (e.g., while the orientation of the user&#39;s face is changing). For example, device  1100  optionally darkens orientation guide  1108  while it is in motion and/or display a fading trail as it tracks movement of the user&#39;s face. In this case, device  1100  optionally reduces this emphasis on orientation guide  1108  relative to user facial image  1106  when the user&#39;s face is not moving. 
     As shown in  FIG. 11B , in response to detecting that the user&#39;s face is oriented towards progress meter portion  1114  (e.g., in accordance with a determination that the image data captured by biometric sensor  1103  includes an angular view of the user&#39;s face), device  1100  updates the display of the progress elements in meter portion  1114  to an “enrolling” state by changing the appearance of the progress elements in meter portion  1114 . For example, device  1100  optionally enlarges and/or changes the color of progress elements in meter portion  1114  while user&#39;s face is oriented towards meter portion  1114 . In some examples, device  1100  elongates the progress ticks and changes their color from grey to blue when updating progress elements to the “enrolling” state. Changing the display of progress elements to the “enrolling” state in this manner indicates that device  1100  is capturing (e.g., enrolling) facial imaging data for the angular view corresponding to the current orientation of the user&#39;s face. In the example of  FIG. 11B , device  1100  maintains progress elements in meter portion  1116  in an unenrolled state to indicate that the user has not yet oriented their face towards meter portion  1116 . In some examples, the display of meter portion  1114  is updated in this manner only if the user&#39;s face is sufficiently rotated towards meter portion  1114  (e.g., if the user&#39;s face is rotated by at least a threshold amount or angle). 
     In some examples, the enrollment progress meter is comprised of a set of progress meter portions such as meter portions  1114  and  1116 . In some examples, each progress meter portion contains a predetermined number of progress elements associated with each portion (e.g., 3, 5, or 8 progress elements). 
     In some examples, as illustrated in  FIG. 11C , device  1100  detects a small rotation and/or tilt of the user&#39;s face and updates the digital viewfinder containing user facial graphic  1106 . For example, the user&#39;s face has begun to tilt downwards and rotate to the right. In the example of  FIG. 11C , however, the user&#39;s face is still oriented towards progress meter portion  1114 . As a result, device  1100  continues to display progress elements of meter portion  1114  in an enrolling state, even though the user begins to rotate and/or tilt their head downwards and to the right. In this case, device  1100  also maintains the display of progress elements proximate to meter portion  1114 , since the user&#39;s head has not been rotated sufficiently to trigger enrollment of the corresponding orientations. 
     As illustrated in  FIG. 11D , device  1100  detects that the user&#39;s face has been rotated and/or tilted towards meter portion  1118 . In the example of  FIG. 11D , the user&#39;s face continues the movement illustrated in  FIG. 11C , tilting downwards and rotating to the right through its initial position in  FIG. 11A , (e.g., the user&#39;s face moves so as not to become oriented towards other portions of enrollment meter  1110 ). In response to detecting the change in facial orientation, device  1100  moves orientation guide  1108 , tracking the movement of user facial image  1106  in the digital viewfinder. In accordance with a determination that the user&#39;s face has become oriented towards meter portion  1118  (e.g., image data captured by biometric sensor  1103  includes a second angular view of the user&#39;s face), device  1100  updates progress elements in meter portion  1118  to the “enrolling” state described above. For example, device  1100  elongates the progress ticks within meter portion  1118  and changes their color. In some examples, device  1100  updates the display of meter portion  1118  only if the corresponding portion of the user&#39;s face has not been enrolled previously (e.g., if the progress elements in meter portion  1118  are in the “unenrolled,” greyed out state). In some examples, device  1100  updates the display of meter portion  1118  regardless of whether the corresponding portion of the user&#39;s face has been previously enrolled (e.g., to provide further indication of the orientation of the user&#39;s face relative to biometric sensor  1103 ). 
     In the example of  FIG. 11D , device  1100  also detects that the user&#39;s face is no longer oriented towards progress meter portion  1114  (since the user&#39;s face is currently oriented towards meter portion  1118 ). In response, device  1100  changes the appearance of progress elements in meter portion  1114  a second time to an “enrolled” state. In the example of  FIG. 11D , device  1100  updates the display of progress ticks in portion  1114  from the elongated “enrolling” state by shortening the progress ticks and changing their color a second time. For example, progress elements in the “enrolled” state are the same length and/or size of progress elements in the “unenrolled” state, but are displayed in green to indicate that the corresponding portion of the user&#39;s face (e.g., the angular view captured in  FIG. 11B ) has been successfully enrolled as described above in connection with  FIG. 11B . 
     In the example of  FIG. 11D , device  1100  maintains progress elements in meter portion  1116  in an unenrolled state to indicate that the user has not yet oriented their face towards meter portion  1116 . 
       FIGS. 11E through 11H  illustrate face enrollment interface  1104  as the user rotates and/or tilts their face in a counter-clockwise motion through a series of orientations associated with the right-hand side of enrollment progress meter  1110 . Beginning from progress meter portion  1118 , device  1100  sequentially changes progress elements in the path of rotation to the “enrolling” state described above based on the user&#39;s facial orientation (e.g., in response to detecting that the user&#39;s face is oriented towards a corresponding portion of progress meter  1110 ). Once the user&#39;s face has rotated past these progress elements (e.g., in response to detecting that the user&#39;s face is no longer oriented towards corresponding portions of progress meter  1110 ), device  1100  updates the progress elements to the “enrolled” state to indicate successful enrollment of corresponding portions of the user&#39;s face. This process is described in more detail below. In some examples, visual characteristics of progress elements in the “enrolling” state is based on the rate at which the user&#39;s facial orientation changes. For example, device  1100  modifies the color of progress elements in the “enrolling” state in a first manner if the user&#39;s face is rotating a first speed, and modifies the color of these progress elements in a second manner if the user&#39;s face is rotating more slowly and/or more quickly. 
     As shown in  FIG. 11E , device  1100  detects that the user&#39;s face has rotated in a counter-clockwise fashion relative to biometric sensor  1103  (e.g., the user&#39;s face rotates up and/or tilts to the left relative to its position in  FIG. 11D ). As described above, device  1100  continuously updates user facial image  1106  to reflect the change in orientation and moves orientation guide  1108  to track the movement of user facial image  1106  in the digital viewfinder. As the user&#39;s face is rotated upwards, device  1100  updates the display of one or more progress elements in meter portion  1116  (e.g.,  1116   a ) to the “enrolling state” (e.g., by elongating and/or changing the color of the one or more progress elements as described above). As shown by the position of user facial image  1106  in  FIG. 11E , the rotation moves the user&#39;s face past (e.g., out of) the orientation corresponding to one or more progress elements in meter portion  1118  (e.g.,  1118   a ). In response to detecting the user&#39;s face is no longer in this orientation, device  1100  updates the display of the one or more progress elements (including  1118   a ) to the “enrolled” state described above to indicate successful enrollment of these portions. In the example of  FIG. 11E , device  1100  maintains one or more elements of progress meter portion  1118  (e.g.,  1118   b ) in the “enrolling” state, since the user&#39;s face has not yet rotated out of the corresponding orientation. Likewise, device  1100  also continues to display one or more progress elements in meter portion  1116  (e.g.,  1116   b ) in the initial “unenrolled” state, since the user&#39;s face has not yet been positioned in a corresponding orientation. 
       FIG. 11F  illustrates face enrollment interface  1104  as counter-clockwise rotation of the user&#39;s face continues relative to its position in  FIG. 11E . Again, device  1100  continuously updates user facial image  1106  to reflect the change in orientation and moves orientation guide  1108  to track the movement of user facial image  1106  in the digital viewfinder. As shown by the position of user facial image  1106  in  FIG. 11F , the rotation moves the user&#39;s face into an orientation corresponding to progress meter portion  1116 . In response to detecting the user&#39;s face in this orientation, device  1100  changes the display of one or more progress elements in meter portion  1116  (e.g.,  1116   b ) from the “unenrolled” state to the “enrolling” state (e.g., by elongating and/or changing the color of the one or more progress elements as described above). As shown by position of user facial image  1106  in  FIG. 11F , the rotation also moves the user&#39;s face past (e.g., out of) the orientation corresponding to the remaining elements of progress meter portion  1118  (e.g.,  1118   b ). In response to detecting the user&#39;s face is no longer in this orientation, device  1100  updates the display of these progress elements (including  1118   b ) to the “enrolled” state described above, indicating successful enrollment of an angular view of the user&#39;s face corresponding to meter portion  1118   b . In the example of  FIG. 11F , device  1100  also continues to display progress elements in meter portion  1120  in the initial “unenrolled” state described above, since the user&#39;s face has not yet been positioned in a corresponding orientation. 
       FIG. 11G  illustrates face enrollment interface  1104  as counter-clockwise rotation of the user&#39;s face continues relative to its position in  FIG. 11F . Again, device  1100  continuously updates user facial image  1106  to reflect the change in orientation and moves orientation guide  1108  to track the movement of user facial image  1106  in the digital viewfinder. As shown by the position of user facial image  1106  in  FIG. 11G , the rotation moves the user&#39;s face into an orientation corresponding to progress meter portion  1120 . In response to detecting the user&#39;s face in this orientation, device  1100  changes the display of progress elements in meter portion  1120  from the “unenrolled” state to the “enrolling” state (e.g., by elongating and/or changing the color of the one or more progress elements as described above). As shown by position of user facial image  1106  in  FIG. 11G , the rotation also moves the user&#39;s face past (e.g., out of) the orientation corresponding to progress meter portion  1116 . In response to detecting the user&#39;s face is no longer in this orientation, device  1100  updates the display of progress elements in meter portion  1116  to the “enrolled” state, indicating successful enrollment of an angular view of the user&#39;s face corresponding to meter portion  1116 . In the example of  FIG. 11G , device  1100  continues to display progress elements in meter portion  1122  in the initial “unenrolled” state, since the user&#39;s face has not yet been positioned in a corresponding orientation. 
       FIG. 11H  illustrates face enrollment interface  1104  as counter-clockwise rotation of the user&#39;s face continues relative to its position in  FIG. 11G . Again, device  1100  continuously updates user facial image  1106  to reflect the change in orientation and moves orientation guide  1108  to track the movement of user facial image  1106  in the digital viewfinder. As shown by the position of user facial image  1106  in  FIG. 11H , the rotation moves the user&#39;s face into an orientation corresponding to progress meter portion  1122 . In response to detecting the user&#39;s face in this orientation, device  1100  changes the display of progress elements in meter portion  1122  from the “unenrolled” state to the “enrolling” state (e.g., by elongating and/or changing the color of the one or more progress elements as described above). In some examples, this orientation causes device  1100  to change the display of one or more progress elements in meter portion  1114  from the “enrolled” state shown in  FIGS. 11D through 11G  to back the “enrolling” state based on the orientation of the user&#39;s face, even though the corresponding facial features have already been enrolled (e.g., to provide further indication of the orientation of the user&#39;s face relative to biometric sensor  1703 ). In this case, device  1100  reverts these elements of progress meter portion  1114  back to the “enrolled” state in response to detecting that the user&#39;s face is no longer oriented in that direction. As shown by position of user facial image  1106  in  FIG. 11H , the rotation also moves the user&#39;s face past (e.g., out of) the orientation corresponding to progress meter portion  1120 . In response to detecting the user&#39;s face is no longer in this orientation, device  1100  updates the display of progress elements in meter portion  1120  to the “enrolled” state, indicating successful enrollment of an angular view of the user&#39;s face corresponding to meter portion  1120 . In the example of  FIG. 11G , device  1100  continues to display the remaining progress elements of enrollment meter  1110  (e.g., progress elements not in meter portions  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) in the initial “unenrolled” state, since the user&#39;s face has not yet been positioned in a corresponding orientation. 
     Enrollment and/or scanning of the user&#39;s facial features proceeds in this manner until all elements of enrollment progress meter  1110  have been transitioned to the enrolled state (e.g., until image data of all corresponding angular views of the user&#39;s face have been captured by biometric sensor  1103 ). For example, enrollment proceeds until the user&#39;s face returns to the orientation corresponding to meter portion  1118  by way of counter-clockwise rotation. 
     Displaying and updating the progress indicator during enrollment in this manner encourages the user to look at the display of device  1100  during the enrollment to improve the ability to detect when gaze is directed at the display, and thus whether or not the user is paying attention to the device. Encouraging the user to look at the display of device  1100  enhances the operability of the device and makes the user-device interface more efficient (e.g., by ensuring that the gaze of the user is directed at the display and thereby ensuring that the biometric feature of the user is properly enrolled) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     It should be appreciated that the examples of  FIGS. 11D through 11H  are merely illustrative. In particular, the enrollment of the user&#39;s facial features can begin at any portion of progress meter  1110  (e.g., meter portion  1114 ). Similarly, angular views of the user&#39;s face corresponding to each meter portion or progress element can be enrolled in any order (e.g., through clockwise rotation). 
       FIG. 11I  illustrates face enrollment interface  1104  after image data of all corresponding angular views of the user&#39;s face have been captured by biometric sensor  1103 . In the example of  FIG. 11I , device  1100  has transitioned the display of all progress elements in enrollment meter  1110  to the “enrolled” state (e.g., during the enrollment process described above in connection with  FIGS. 11B-11H ). For example, device  1100  changes the color of progress element to green to indicate successful enrollment. In the example of  FIG. 11I , device  1100  displays text prompt  1124  indicating that a first scan of the user&#39;s facial features is complete. In some examples, device  1100  issues audio and/or tactile notification  1126  to provide an additional indication that the first scan is complete. In some examples, the audio and/or tactile output that indicates successful enrollment of the user&#39;s facial features is the same as an audio and/or tactile output that is used to indicate successful face authentication at device  1100 . In the example of  FIG. 11I , device  1100  continues to display user facial image  1106 . In some examples, user facial image  1106  is still part of a live preview of the digital viewfinder. In other examples, device  1100  displays a single (e.g., still) user image captured during the enrollment process. In the example of  FIG. 11I , device  1100  ceases to display orientation guide  1108  once the scan is complete. 
     As illustrated in  FIGS. 11J-11K , in some examples, device  1100  displays an animation that transitions the display of enrollment progress meter  1110  to success-state meter  1128  shown in  FIG. 11K . For example, device  1100  reduces the length of each progress tick mark as illustrated in  FIG. 11J  and merges the display of the previously discrete progress elements into a continuous circle. In the example of  FIG. 11K , after displaying the animation, device  1100  displays scan completion interface  1130 . Scan completion interface  1130  includes user facial image  1132  and success-state meter  1128 . In the example of  FIG. 11K , user facial image  1132  is blurred, faded, darkened or otherwise obscured to indicate that additional image data is no longer being collected as part of the facial scan. In some examples, success-state meter  1128  is a solid, continuous green circle surrounding user facial image  1132  that provides a visual indication that the first scan is complete. To provide a further visual notification, scan completion interface  1130  also includes text prompt  1134  (e.g., a completion message). Scan completion interface  1130  also includes continue affordance  1136 . In some examples, while displaying enrollment completion interface  1130 , device  1100  detects activation (e.g., selection) of continue affordance  1136  (e.g., by way of user input  1137 ). In some examples where display is touch-sensitive, user input  1337  is a tap, swipe or other gesture on the display surface substantially on continue affordance  1136 . In other examples, activation of continue affordance  1136  is a keyboard input or activation of the affordance with a focus selector (e.g., a mouse cursor). 
     In some examples, after completion of the enrollment process described above with respect to  FIGS. 11B-11G , a second iteration of facial enrollment is performed. As shown in  FIG. 11L , in response to detecting activation of continue affordance  1136 , device  1100  displays second face enrollment interface  1138 . In the example of  FIG. 11L , second face enrollment indicator includes second user facial image  1140  and second enrollment progress meter  1142 . In some examples, second user facial image  1140  is a representation of the field of view of biometric sensor  1103  that has a similar visual treatment to user facial image  1106  (e.g., second user facial image  1140  is a live preview of image data captured by biometric sensor  1103  displayed as a digital viewfinder). In some examples, device  1100  displays a second orientation guide  1144  superimposed (e.g., overlaid on) second user facial image  1140 . In the example of  FIG. 11L , second orientation guide  1144  has a similar visual treatment to orientation guide  1108  (e.g., second orientation guide  1144  includes a number of curved lines that appear to extend out of the plane of display  1102  into a virtual z dimension). In some examples, second enrollment progress meter  1142  is comprised of a set of progress elements (e.g.,  1142   a ,  1142   b ,  1142   c ) that are spaced around second user facial image  1140 . In some examples, portions of second enrollment progress meter  1142  (e.g., meter portions  1146  and  1148 ) optionally correspond to particular orientations or portions of the user&#39;s face with respect to biometric sensor  1103 . In some examples, some or all of the meter portions optionally include a greater number of progress elements than the respective portions of enrollment progress meter  1110 . By way of example, each portion of second progress meter  1142  corresponds to the same facial orientation or angular view of the user&#39;s face as the corresponding portions of progress meter  1140  (e.g., meter portion  1146  corresponds to the same facial orientation as meter portion  1114  in  FIGS. 11B-11H ). In some examples, upon display of second enrollment interface  1138 , device  1100  sets the visual state of progress elements in enrollment progress meter  1142  to the “unenrolled” state described above (e.g., enrollment progress from the first enrollment scan is reset). In the example of  FIG. 11L , second face enrollment interface also includes text prompt  1150 , which instructs the user to move (e.g., rotate and/or tilt) their head in a circular motion during the second enrollment process. 
     In some examples, as the second iteration of facial enrollment is performed, device  1100  updates the display of second user facial image  1140 , second progress meter  1142 , and orientation guide  1144  in response to changes in the orientation of the user&#39;s face with respect to biometric sensor  1103 . For example, the user repeats the same (or similar) motion of his or her face that were performed in the first iteration of enrollment, and device  1100  updates the display of these elements of second user interface  1138  in the manner (or similar manner) described above with respect to  FIGS. 11B-11H . 
       FIG. 11M  illustrates second face enrollment interface  1128  after the second iteration of enrollment is complete (e.g., after image data of several angular views of the user&#39;s face have been captured by biometric sensor  1103 ). In the example of  FIG. 11M , device  1100  has transitioned the display of all progress elements in second enrollment meter  1142  to the “enrolled” state described above. For example, the color of each progress element has been changed to green to indicate successful enrollment. In the example of  FIG. 11M , device  1100  displays text prompt  1152  indicating that the second scan of the user&#39;s facial features is complete. In some examples, device  1100  issues audio and/or tactile notification  1154  to provide an additional indication that the second scan is complete. In some examples, audio and/or tactile notification  1154  is the same as tactile notification  1126  that is issued to indicate completion of the first scan. In some examples, the audio and/or tactile output that indicates a successful second scan of the user&#39;s facial features is the same as an audio and/or tactile output that is used to indicate successful face authentication at the device. In the example of  FIG. 11M , device  1100  continues to display second user facial image  1140 . In some examples, second user facial image  1140  is part of a live preview of the digital viewfinder. In other examples, device  1100  displays a single (e.g., still) user image captured during the enrollment process. In the example of  FIG. 11M , device  1100  ceases to display second orientation guide  1144  once the scan is complete. 
     In the example of  FIG. 11N , after issuing the notification indicating completion of the second scan, device  1100  displays second scan completion interface  1156 . Second scan completion interface  1156  includes user facial image  1158  and second success-state meter  1160 . In the example of  FIG. 11N , user facial image  1158  is blurred, faded, darkened or otherwise obscured to indicate that additional image data is no longer being collected as part of the second facial scan. In some examples, second success-state meter  1160  is a solid, continuous green circle surrounding user facial image  1158  that provides a visual indication that the first scan is complete (e.g., similar to success-state meter  1128 ). To provide a further visual notification, second scan completion interface  1156  also includes text prompt  1162  (e.g., a second scan completion message). Second scan completion interface  1156  also includes continue affordance  1164 . In some examples, while displaying second scan completion interface  1156 , device  1100  detects activation (e.g., selection) of continue affordance  1164  (e.g., by way of user input  1165 ). In some examples where display  1102  is touch-sensitive, the activation is a tap, swipe or other gesture on the display surface substantially on continue affordance  1164 . In other examples, activation of continue affordance  1164  is a keyboard input or activation of the affordance with a focus selector (e.g., a mouse cursor). In the example of  FIG. 11N , user facial image  1158  is blurred, faded, darkened or otherwise obscured to indicate that additional image data is no longer being collected during the second facial scan. 
     In the example of  FIG. 11O , in response to detecting activation of continuation affordance  1164 , device  1100  displays enrollment completion interface  1166 . As shown in  FIG. 11O , enrollment completion interface  1166  includes biometric authentication glyph  1168 . For example, biometric authentication glyph is, optionally, a line drawing of all or part of a face (e.g., a stylized face graphic). In the example of  FIG. 11O , enrollment completion interface  1166  also includes text prompt  1170  indicating that the enrollment process is complete and face authentication at the device is set-up and/or enabled. In some examples, enrollment completion interface  1166  also includes completion affordance  1172 , activation of which causes device  1100  to exit face authentication set-up. In some examples, enrollment completion interface  1166  does not include facial image  1158 . 
       FIG. 12A-12B  is a flow diagram illustrating a method for registering a biometric feature of the user on an electronic device in accordance with some examples. Method  1200  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1100 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric features by the one or more biometric sensors. Some operations in method  2000  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  1200  provides an intuitive way to register a biometric feature of the user on an electronic device. The method reduces the cognitive burden on a user for enrolling a biometric feature on the device, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to enroll a biometric feature faster and more efficiently conserves power and increases the time between battery charges 
     The device displays ( 1202 ), on the display, a biometric enrollment interface (e.g.,  1104 ). Displaying the biometric enrollment interface includes displaying ( 1204 ) a representation of a biometric feature (e.g.,  1106 ). For example, the representation of the biometric feature is, optionally, a representation of a face, fingerprint, iris, handprint, or other physical biometric feature that can be used to distinguish one person from another person in a field of view of one or more cameras of the device (e.g., a representation of the head of a user of the device). The representation of the biometric feature has an orientation determined based on an alignment of the biometric feature to one or more biometric sensors of the device (e.g.,  1103 , based on camera data that includes the user&#39;s head positioned in the field of view of one or more of the cameras). 
     In some examples, the device displays ( 1206 ) a digital viewfinder (e.g., live preview of image data containing  1106 ) including a representation of a field of view of the one or more cameras (e.g.,  1103 ). For example, in some examples, the device displays a live preview of image data captured by the one or more cameras. In some examples, the representation of the field of view of the one or more cameras has background content removed. The background optionally is determined based on depth information captured by the one or more cameras (e.g., removing the background content optionally includes removing any background or simply vignetting). In some examples, the device does not perform any background removal. 
     Displaying the biometric enrollment interface also includes concurrently displaying ( 1208 ) a progress indicator (e.g.,  1110 ) including a first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 , a first set of objects (e.g.,  1110   a ,  1110   b , and  1110   c , or  1116   a  and  1116   b , or  1118   a  and  1118   b ) spaced around the representation of the biometric feature such as a first set of tick marks) at a first position on the display relative to the representation of the biometric feature (e.g.,  1106 ) and a second progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122  a second set of objects (e.g.,  1110   a ,  1110   b , and  1110   c , or  1116   a  and  1116   b , or  1118   a  and  1118   b ) spaced around the representation of the biometric feature such as a second set of tick marks) at a second position on the display relative to the representation of the biometric feature (e.g.,  1106 ). The representation of the biometric feature (e.g.,  1106 ) is displayed between the first position and the second position on the display. Displaying the progress indicator during enrollment in this manner encourages the user to look at the display of the electronic device during the enrollment to improve the ability to detect when gaze is directed at the display, and thus whether or not the user is paying attention to the device. Encouraging the user to look at the display of the electronic device enhances the operability of the device and makes the user-device interface more efficient (e.g., by ensuring that the gaze of the user is directed at the display and thereby ensuring that the biometric feature of the user is properly enrolled) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the progress indicator includes ( 1210 ) a plurality of progress-indicator portions (e.g.,  1114 ,  1116 ,  1118 ,  1120 ,  1122 , each progress indicator portion includes one or more progress elements (e.g.,  1110   a ,  1110   b ,  1110   c ,  1116   a ,  1116   b ,  1118   a ,  1118   b )). In some examples, the plurality of progress-indicator portions include the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) and the second progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ), and the plurality of progress-indicator portions surrounds at least a portion of the representation of the biometric feature (e.g.,  1106 ). In some examples, one or more of the plurality of progress indicator portions includes ( 1212 ) a plurality of respective progress elements (e.g.,  1110   a ,  1110   b ,  1110   c ,  1118   a ,  1118   b ). In some examples, the progress indicator optionally includes a set of one or more display elements (e.g.,  1110   a ,  1110   b ,  1110   c ,  1116   a ,  1116   b ,  1118   a ,  1118   b ) arranged around the representation of the biometric feature (e.g.,  1106 ). For example, these display elements optionally is a circle of radially extending lines indicating progress of enrollment lines (“ticks”) around the user&#39;s face. The lines optionally indicate the direction in which respective changes of orientation of the biometric feature are sufficient for enrollment the biometric feature (e.g., point upward to get upper lines to move, even though bottom of biometric feature is being scanned). In some examples, a first set of lines correspond to the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) and a second set of lines correspond to the second progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ). For example, a predetermined number of ticks (e.g., 8) are associated with each portion of the progress indicator. 
     In some examples, the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) indicates ( 1214 ) the enrollment status of a first portion of the biometric feature that is detected by (e.g., visible to) the one or more biometric sensors (e.g.,  1103 ) when the biometric feature (e.g., the user&#39;s face) is turned toward the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ). For example, the upper right portion of the progress indicator (e.g.,  1120 ) changes in appearance when the user&#39;s face turns toward the upper right portion of the device to enroll the lower left portion of the user&#39;s face. Likewise, in some examples, the second progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) indicates the enrollment status of a second portion of the biometric feature, different from the first portion of the biometric feature, that is detected by (e.g., visible to) the one or more biometric sensors (e.g.,  1103 ) when the biometric feature (e.g., the user&#39;s face) is turned toward the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ). For example, the lower right portion of the progress indicator (e.g.,  1118 ) changes in appearance when the user&#39;s face turns toward the lower left portion of the device to enroll the upper right portion of the user&#39;s face. 
     In some examples, displaying ( 1202 ) the biometric enrollment interface (e.g.,  1104 ) further includes displaying a prompt (e.g.,  1112 ) to move the biometric feature. In some examples, the displayed prompt optionally is accompanied by a tactile and/or auditory prompt. In some examples, the types of responses are provided are based on settings of the electronic device and/or manually controlled by a user. Providing a prompt with instructions on how to properly move the biometric feature provides feedback to the user that allows them to quickly recognize and execute the required movements, reducing the amount of time required to complete the enrollment process. Providing improved visual prompting regarding proper inputs required for biometric enrollment therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device displays a prompt (e.g.,  1108 ) indicating a direction of movement. In some examples, the prompt is an orientation guide (e.g.,  1108 ) overlaid on biometric enrollment interface (e.g.,  1104 ). In some examples, the prompt is overlaid on the representation of the biometric feature (e.g.,  1106 ). In some examples, the device overlays a three-dimensional object (e.g.,  1108 ) on the representation of the biometric feature (e.g.,  1106 ). For example, the three-dimensional object optionally is an arc that extends into a virtual z-dimension and moves as the user&#39;s head is rotated. In some examples, the three-dimensional object (e.g.,  1108 ) includes a plurality of arcs that extend into a virtual z-dimension (e.g., two arcs that cross each other at a point in front of the user&#39;s face). In some examples, the three-dimensional object (e.g.,  1108 ) is emphasized when the user is moving (e.g., the three-dimensional object darkens or displays a fading trail as it moves with the movement of the biometric feature), which emphasizes the three-dimensional object when it is in motion and reduces the emphasis on the three-dimensional object relative to the representation of the biometric feature when the biometric feature is not in motion. 
     While concurrently displaying the representation of the biometric feature (e.g.,  1106 ) and the progress indicator (e.g.,  1110 ), the device detects ( 1216 ) a change in the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1103 ). 
     In some examples, in response to detecting the change in the orientation of the biometric feature relative to the one or more biometric sensors ( 1218 ), the device rotates the prompt (e.g.,  1108 ) in accordance with the change in the orientation of the biometric feature to the one or more biometric sensors (e.g.,  1103 ). In some examples, rotating the prompt includes rotating the three-dimensional object (e.g.,  1108 ) at least partially into a virtual z-dimension of the display. Rotating the orientation guide overlaid on the representation of the biometric feature provides the user with feedback about the orientation of his or her biometric features relative to the biometric sensors of the device in three-dimensional space, enabling the user to place his or her biometric features more quickly move the biometric feature through the required range of orientations during the enrollment process. Providing improved visual feedback regarding the orientation of the biometric feature to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in response to detecting the change in the orientation of the biometric feature to the one or more biometric sensors, the device updates ( 1220 ) the representation of the biometric feature (e.g.,  1106 ) in accordance with the change in the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1103 ). For example, in some examples, the orientation of the representation of the biometric feature (e.g.,  1106 ) is changed without regard to whether enrollment criteria are met. In some examples, the orientation of the representation of the biometric feature (e.g.,  1106 ) is only changed if the enrollment criteria are met. Updating the orientation of the displayed representation of the biometric feature provides the user with feedback about the orientation of his or her biometric features relative to the biometric sensors of the device, enabling the user to more quickly move the biometric feature through the required range of orientations during the enrollment process. Providing improved visual feedback regarding the orientation of the biometric feature to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ), the device updates ( 1222 ) one or more visual characteristics of the first progress-indicator portion. For example, the determining the change in the orientation of the biometric feature that meets enrollment criteria optionally is based on determining that the image data includes data corresponding to a first angular view of the face of the user from a first perspective angle (e.g., a bottom perspective of the face, such as when the user&#39;s face is tilted up). Updating the visual state of a portion of the progress meter corresponding to the current orientation of the biometric feature allows the user to recognize that a portion of the biometric feature is properly oriented for enrollment. This in turn indicates to the user how to change the orientation of the biometric feature to enroll other portions that correspond to other respective parts of the progress meter, reducing the amount of time required to complete the enrollment process. Providing improved visual feedback regarding the enrollment state of a biometric feature to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the enrollment criteria for the first portion of the biometric feature that corresponds to the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) includes a requirement that the first portion of the biometric feature is oriented relative to the one or more biometric sensors (e.g.,  1103 ) in a predetermined manner (e.g., that the user&#39;s face is looking toward the first progress-indicator portion). 
     In some examples, the enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) include a requirement that the first portion of the biometric feature has not been enrolled. 
     In some examples, the enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) includes ( 1224 ) a requirement that the first portion of the biometric feature change in orientation (e.g., rotate) relative to the one or more biometric sensors (e.g.,  1103 ) by at least a threshold amount. In some examples, enrollment of the first portion of the biometric feature requires that the biometric feature move (rotate) sufficiently such that the first portion can be properly captured by the one or more biometric sensors (e.g.,  1103 ). 
     In some examples, updating one or more visual characteristics of the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) includes updating the one or more visual characteristics of the first progress-indicator portion in a first manner (e.g. color) based on an enrollment state of the first portion of the biometric feature and updating the one or more visual characteristics of the first progress-indicator portion in a second manner (e.g., size or length of progress elements) based on the alignment of the biometric feature to the one or more biometric sensors (e.g.,  1103 ) of the device. For example, the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) changes from black to green when a portion of the biometric feature that corresponds to the first-progress indicator portion has been enrolled and one or more lines (e.g.,  1110   a ,  1110   b ,  1110   c ,  1116   a ,  1116   b ,  1118   a ,  1118   b ) corresponding in the first progress-indicator portion are elongated when the portion of the biometric feature that corresponds to the first-progress indicator portion are facing the one or more biometric sensors (e.g.,  1103 ). In some examples, updating the one or more visual characteristics of the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) in a second manner is based on the direction of change in the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1103 ). In some examples, updating in the second manner is performed additionally or alternatively based on the rate of change of the orientation of the biometric feature relative to the one or more biometric sensors. Changing a portion of the progress meter corresponding to the current orientation of the biometric feature from a first visual state to a second visual state allows the user to quickly recognize that a portion of the biometric feature is properly oriented for enrollment. This can in turn indicate to the user how to change the orientation of the biometric feature to enroll other portions that correspond to other respective parts of the progress meter, which reduces the amount of time required to complete the enrollment process. Providing improved visual feedback regarding the enrollment state of a biometric feature to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device updates the one or more visual characteristics of the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) based on a rate of change in the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1103 ). In some examples, updating the one or more visual characteristics in this manner includes modifying the color of the first progress-indicator portion based on the rate of change in the orientation of the biometric feature. 
     In some examples, the first progress indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) includes a plurality of display elements in a respective order (e.g.,  1110   a ,  1110   b ,  1110   c ,  1114   a ,  1116   a ,  1116   b ,  1118   a ,  1118   b ). In accordance with a determination that the change in the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1103 ) is a change in a first direction (e.g. a clockwise rotation), the device optionally changes an appearance of the display elements starting from a first end of the respective order (e.g., starting at  1118   a ). For example, the device optionally starts to elongate lines in the first progress-indicator portion starting from a first side of the respective order moving to second side of the respective order (to  1114   a ). In accordance with a determination that the change in the orientation of the biometric feature relative to the one or more biometric sensors is a change in a second direction (e.g. counter-clockwise rotation), the device optionally changes an appearance of the display elements (e.g.,  1110   a ,  1110   b ,  1110   c ,  1114   a ,  1116   a ,  1116   b ,  1118   a ,  1118   b ) starting from a second end of the respective order that is different from the first end of the respective order (e.g., starting from  1114   a ). For example, the device optionally elongates lines in the first progress-indicator portion starting from the second side of the respective order moving to the first side of the respective order (e.g., to  1118   a ). In some examples, a similar approach is taken when changing an appearance of the second progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) or other progress indicator portions. 
     In some examples, the device updates the one or more visual characteristics of the first progress-indicator (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) from a first state (e.g., “unenrolled”) to a second state (e.g., “enrolling”) that indicates that the first progress-indicator portion meets the enrollment criteria. For example, the device enlarges, grows or changes the color of display elements in a portion of the progress indicator (e.g.,  1114 ) toward which the biometric feature is currently oriented, such as the portion of the progress indicator toward which the user&#39;s face is pointed (e.g., orientation of the  1106  in  FIG. 11B ). 
     In some examples, after updating one or more visual characteristics of the first progress-indicator portion, the device optionally detects a change in orientation of the biometric feature relative to the one or more biometric sensors so the biometric feature no longer meets enrollment criteria for a first portion of the biometric feature that corresponds to the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ). In response to detecting the change in orientation of the biometric feature relative to the one or more biometric sensors, the device optionally updates ( 1226 ) the one or more visual characteristics of the first progress-indicator portion from the second state (e.g., “enrolling”) to a third state (e.g., “enrolled”) that indicates that the first portion of the biometric feature has been enrolled but no longer meets the enrollment criteria. For example, the device optionally changes the appearance of the progress-indication portions (e.g., the color or size) a second time when the user&#39;s face moves away from them, and optionally transitions the first portion of the progress indicator (e.g.,  1114   a ) from “tilted toward” appearance to enrolled appearance when user orients biometric feature away from the portion of the progress indicator (e.g., orientation of  1106  in  FIG. 11D ). One visual property of the progress indicator (e.g., color) optionally indicates the enrollment state (e.g., blue for “tilted toward” green for “enrolled” grey for “unenrolled”), while another visual property of the progress indicator (e.g., length of lines) indicates direction of orientation of biometric feature. Progress optionally advances around progress indicator (e.g.,  1110 ) based on direction and speed of change of tilting. For example, progress indicator lines (e.g.,  1110   a ,  1110   b ,  1110   c ,  1114   a ,  1116   a ,  1116   b ,  1118   a ,  1118   b ) optionally bulge based on the direction and speed of movement of the biometric feature and/or change color based on direction and speed of movement of biometric feature. Changing a portion of the progress meter corresponding to the current orientation of the biometric feature from a second visual state to a third visual state allows the user to quickly recognize that a portion of the biometric feature has been successfully enrolled. This also indicates to the user that they no longer need to move the biometric feature into that orientation during the enrollment process, which directs the user&#39;s attention to enrolling other portions of the biometric feature, reducing the amount of time required to complete the enrollment process. Providing improved visual feedback regarding the enrollment state of a biometric feature to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for a second portion of the biometric feature that corresponds to the second progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ), the device updates ( 1228 ) one or more visual characteristics of the second progress-indicator portion. For example, determining the change in the orientation of the biometric feature that meets enrollment criteria optionally are based on determining that the image data includes data from the face of the user corresponding to a second, different angular view of the face of the user from a second, different perspective angle (e.g., a left-side perspective of the face, such as when the user&#39;s face is tilted to the right). In some examples, updating the visual characteristics of the second progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) optionally include some or all of the steps described above in connection with updating the visual characteristics of the first progress-indicator portion. Updating the visual state of a second portion of the progress meter corresponding to the current orientation of the biometric feature allows the user to recognize that a second portion of the biometric feature is properly oriented for enrollment. This in turn indicates to the user how to change the orientation of the biometric feature to enroll other portions that correspond to other respective parts of the progress meter, reducing the amount of time required to complete the enrollment process. Providing improved visual feedback regarding the enrollment state of a biometric feature to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in accordance with a determination that enrollment-completion criteria are met (e.g., all portions of the biometric feature have been enrolled,  1110  in  FIG. 11E ), the device outputs an indication (e.g.,  1124 ,  1126 ) that enrollment of the biometric feature is complete. 
     For example, the device optionally updates one or more visual characteristics of the progress indicator (e.g.,  1110 , e.g., merge a plurality of the progress indicator display elements (e.g.,  1110   a ,  1110   b ,  1110   c ,  1114   a ,  1116   a ,  1116   b ,  1118   a ,  1118   b ) into a continuous shape such as a circle). In some examples, prior to detecting a change in the orientation of the biometric feature relative to the one or more biometric sensors, the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) and the second progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120 , or  1122 ) are visually discrete. In this case, updating one or more visual characteristics of the progress indicator includes visually merging the first progress-indicator portion and the second progress-indicator portion. 
     In some examples, the device modifies the representation of the biometric feature (e.g.,  1106 ,  1132 ). In some examples, the representation of the biometric feature is blurred, faded, darkened and/or otherwise obscured to indicate that additional information about the biometric feature is no longer being collected as part of the enrollment process. 
     In some examples, the device displays a confirmation affordance (e.g.,  1136 ,  1164 ) and selection of the confirmation of the causes the electronic device to display a completion interface (e.g.,  1166 ). In some examples, the device displays a simulation of a representation of the biometric feature (e.g.,  1168 ). In some examples, the simulation of the representation of the biometric feature is two dimensional. In some examples, the simulation of the representation of the biometric feature is three-dimensional. 
     In some examples, the device outputs an indication (e.g.,  1126 ,  1154 ,  1122 ,  1162 ,  1170 ) that an enrollment procedure is complete (e.g., a tactile output). In some examples, the device outputs a tactile output (e.g.,  1126 ,  1154 ) that indicates successful enrollment of the biometric feature. In some examples, the tactile output that indicates successful enrollment of the biometric feature is the same as a tactile output that is used to indicate successful authentication with the biometric feature. 
     In some examples, after outputting an indication that enrollment of the biometric feature is complete, the device displays a second biometric enrollment interface (e.g.,  1138 ). In some examples, after completion of first enrollment, a second iteration of enrollment is performed. This second iteration of enrollment is optionally performed in response to a selection of an affordance (e.g.,  1136 ). Performing a second scan of the user&#39;s biometric features allows the device to capture additional biometric data corresponding to different orientations or positions of the biometric feature that may not have been recorded during the first iteration of enrollment. Performing a second scan of the user&#39;s biometric features therefore allows for more efficient and/or secure biometric authorization at the device, enhancing the operability of the device and making the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In the second biometric enrollment interface, the device displays a second representation of a biometric feature ( 1140 ). The second representation of the biometric feature optionally has an orientation determined based on an alignment of the biometric feature to one or more biometric sensors of the device (e.g.,  1103 ). In some examples, the second representation of the biometric feature is a representation of a field of view of the one or more cameras that has a similar visual treatment to the first representation of the biometric feature (e.g.,  1106 ). 
     In the second biometric enrollment interface, the device concurrently displays a second progress indicator (e.g.,  1142 ) including a third progress-indicator portion (e.g., a first set of objects spaced around the representation of the biometric feature such as  1146 ) at the first position on the display relative to the representation of the second biometric feature (e.g.,  1140 ) and a fourth progress-indicator portion (e.g., a second set of objects spaced around the representation of the biometric feature such as  1148 ) at the second position on the display relative to the second representation of the biometric feature (e.g.,  1140 ). The second representation of the biometric feature is displayed between the third position and the fourth position on the display. In some examples, the third progress-indicator portion corresponds to a same portion of the biometric feature as the first progress-indicator portion (e.g.,  1114 ). In some examples, the fourth progress-indicator portion corresponds to a same portion of the biometric feature as the second progress-indicator portion (e.g.,  1118 ). 
     In some examples, an enrollment state of the first progress-indicator portion (e.g.,  1114 ,  1116 ,  1118 ,  1120  or  1122 ) does not correspond to an enrollment state of the third progress-indicator portion (e.g.,  1146  or  1148 ). 
     In some examples, the first progress-indicator portion of the progress indicator includes a first number of progress elements (e.g.,  1114   a ) and the third progress-indicator portion of the second progress indicator includes a second number of progress elements (e.g.,  1142   a ,  1142   b ,  1142   c ) that is different (e.g., greater) than the first number. In some examples, a plurality (or all) of the progress-indicator portions (e.g.,  1146 ,  1148 ) in the second progress indicator (e.g.,  1142 ) include more progress elements than the corresponding progress-indicator portions (e.g.,  1114 ,  1118 ) in the first progress indicator (e.g.,  1110 ). 
     In some examples, while concurrently displaying the second representation of the biometric feature (e.g.,  1140 ) and the second progress indicator (e.g.,  1142 ), the device detects a second change in the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1103 ). In response to detecting the second change in the orientation of the biometric feature relative to the one or more biometric sensors, and in accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for the first portion of the biometric feature, the device updates one or more visual characteristics of the third progress-indicator portion (e.g.,  1146  or  1148 ). In accordance with a determination that the change in the orientation of the biometric feature meets enrollment criteria for the second portion of the biometric feature, the device updates one or more visual characteristics of the fourth progress-indicator portion (e.g.,  1146  or  1148 ). For example, in order to advance through the second enrollment step of the enrollment process the user repeats the changes in orientation of the biometric feature that were used to enroll the biometric feature in the first enrollment step of the enrollment process in the second enrollment step of the enrollment process. Thus, updating visual characteristics of the third and fourth progress-indicator portions optionally include steps similar to those described above in connection with the first and second progress-indicator portions (e.g.,  1114 ,  1116 ,  1118 ,  1120  or  1122 ). 
     In some examples, after detecting the second change in the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1103 ), and in accordance with a determination that a second set of enrollment-completion criteria are met (e.g., all portions of the biometric feature have been enrolled), the device outputs a second indication (e.g.,  1162 ,  1163 ) that enrollment of the biometric feature is complete. In some examples, enrollment does not actually take place; rather, the process is emulated visually. In some examples, the second indication is a visual, auditory, and/or tactile output (e.g.,  1163 ) indicating that enrollment of the biometric feature is complete. In some examples, the second indication is the same as the indication provided in accordance with a determination that the first set of enrollment-completion criteria are met (e.g.,  1126 ). 
     Note that details of the processes described above with respect to method  1200  (e.g.,  FIGS. 12A-12B ) are also applicable in an analogous manner to the methods described herein. For example, method  1200  optionally includes one or more of the characteristics of the various methods described herein with reference to methods  800 ,  1000 ,  1400 ,  1600 ,  1800 ,  2000 ,  2200 ,  2500 , and  2700 . For example, the face enrollment confirmation interface as described in method  1000  can be applied with respect to the face enrollment user interface (e.g.,  1104 ). For another example, hints as described in method  1400  can be applied with respect to the face enrollment user interface (e.g.,  1104 ). For another example, transitioning a progress meter as described in method  800  can be applied with respect to the enrollment progress meter (e.g.,  1110 ). For brevity, these details are not repeated below. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 12A-12B  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, displaying operation  1202 , displaying operation  1208 , detecting operation  1216 , updating operation  1222 , and updating operation  1224  are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 13A-13R  illustrate exemplary user interfaces for registering a biometric feature on an electronic device (e.g., device  100 , device  300 , device  500 , device  700 , device  900 , or device  1100 ), in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIG. 14 . 
       FIG. 13A  illustrates an electronic device  1300  (e.g., portable multifunction device  100 , device  300 , device  500 , device  700 , device  900 , or device  1100 ). In the exemplary example illustrated in  FIGS. 13A-13R , electronic device  1300  is a smartphone. In other examples, electronic device  1300  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  1300  has a display  1302 , one or more input devices (e.g., touchscreen of display  1302 , a button, a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  903 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  1303  are the one or more biometric sensors  703 . In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     As illustrated in  FIG. 13A , device  1300  displays a face enrollment user interface  1304  on display  1302 . In some examples, face enrollment user interface  1304  is displayed after device  1300  detects successful alignment of the user&#39;s face relative its one or more cameras as described above in connection with  FIGS. 9A-9Y . In some examples, face enrollment interface  1304  has similar visual characteristics as face enrollment interface  1104  described above in connection with  FIG. 11A . Face enrollment interface  1304  includes user facial image  1306 . In some examples, user facial image  1306  is an image of the user captured by one or more cameras on device  1300  (e.g., biometric sensor  1303 ). For example, user facial image  1306  is, optionally, a live preview of the image data captured by the one or more cameras (e.g., a digital viewfinder) that updates continuously as the field of view of the camera and/or the field of view&#39;s contents change. In some examples, background content is removed such that the only the user&#39;s face is visible in facial image  1306 . Face enrollment interface  1304  also includes orientation guide  1308  that is superimposed (e.g., overlaid) on user facial image  1106 . As described above in connection with  FIGS. 7I-7K , orientation guide  1308  optionally is a set of curved lines (e.g., crosshairs) that extend into a virtual z-dimension (e.g., along an axis normal to the plane of the display) and intersect over the center of user facial image  1306 . Thus, the curved lines of orientation guide  1308  optionally appears to bulge outwards relative to the plane of display  1302  to give a sense of the position of the user&#39;s head in three-dimensional space. 
     Face enrollment user interface  1304  includes enrollment progress meter  1310 . Enrollment progress meter  1310  includes a set of display elements (e.g., progress elements  1310   a ,  1310   b , and  1310   c ) that are arranged around user facial image  1306  and orientation guide  1308 . In the example of  FIG. 13A , the progress elements are a set of lines that extend radially outward from user facial image  1306  and are arranged in a circular pattern. In some examples, progress elements  1310   a ,  1310   b ,  1310   c , etc. indicate an orientation of the user&#39;s face needed to enroll corresponding facial features. For example, progress elements in the upper portion of enrollment meter  1310  optionally move, fill in, elongate, and/or change color (e.g., in the manner of  FIGS. 11B-11H ) when the user&#39;s head is tilted upwards, which allows the one or more cameras on device  1300  to capture image data of the under-side of the user&#39;s face. In the example of  FIG. 13A , device  1310  displays progress elements in enrollment progress meter  1310  in an unenrolled state (e.g., the progress elements are greyed out). 
     In the example of  FIG. 13A , face enrollment interface  1304  includes text prompt  1312 , which instructs the user to begin moving their face relative to the device in order to advance enrollment progress meter  1310  (e.g., enroll their facial features). In some examples, device  1300  displays text prompt  1312  before any portion of the user&#39;s face as been enrolled. 
     While displaying face enrollment interface  1304 , device  1300  detects criteria for displaying enrollment prompts (e.g., hints). In some examples, the enrollment prompt criteria include a requirement that the user&#39;s face has moved less than a first threshold amount in a predetermined time period, as determined by biometric sensor  1303 . 
     In some examples, in response to detecting that these enrollment hint criteria are met, device  1300  displays audio hint enablement interface  1314  as shown in  FIGS. 13B and 13C . In the example of  FIG. 13B , hint enablement interface  1314  includes text prompt  1316 , informing the user of the option to either enable or disable audio hints. Accordingly, in some examples, hint enablement interface  1314  includes yes affordance  1318  and no affordance  1320 . In some examples, in response to activation (e.g., selection) of no affordance  1320 , device  1300  displays face enrollment interface  1304  a second time, allowing the user to proceed with enrollment of his or her facial features without the prompts and/or hints described below. In the example of  FIG. 13C , however, device  1300  detects activation (e.g., selection) of yes affordance  1310 . In some examples, the activation is a user input at contact area  1322  (e.g., a tap or swipe gesture). 
     In response to detecting activation of yes affordance  1320 , device  1300  displays hint-enabled enrollment interface  1324 , for example, as illustrated in the example of  FIG. 13D . In some examples, hint-enabled enrollment interface  1324  or one or more of the prompts described below are displayed whether or not the user has enabled audio hints (e.g., in response to detecting that the user&#39;s face has not moved sufficiently in a pre-determined period of time). In the example of  FIG. 13D , hint-enabled enrollment interface  1324  includes user facial image  1326  that has similar or identical visual characteristics to user facial image  1306 . For example, in some examples, user facial image  1326  is an image of the user captured by one or more cameras on device  1300  (e.g., biometric sensor  1303 ). For example, user facial image  1326  is, optionally, a live preview of the image data captured by biometric sensor  1303  (e.g., a digital viewfinder) that updates continuously as the field of view of the camera and/or the field of view&#39;s contents change. In some examples, hint-enabled enrollment interface  1324  includes visual movement prompt  1328  that is, optionally, overlaid (e.g., superimposed) on user facial image  1326 . In the example of  FIG. 13D , visual movement prompt  1328  includes an arrow element indicating a requested direction in which the user should move (e.g., rotate and/or tilt) his or her face in order to enroll a corresponding portion (e.g., angular view) of the face. In some examples, visual movement prompt  1328  is partially transparent such that the underlying user facial image  1326  is also visible. In the example of  FIG. 13D , the arrow element of visual movement prompt  1328  instructs the user to move (e.g., rotate, tilt, or turn) their face to the right (e.g., towards a right portion of enrollment progress meter  1330  in order to enroll an angular view of the left side of the user&#39;s face). 
     In some examples, device  1300  displays text prompt  1332 , providing written instructions to user that match visual movement prompt  1328 . In the example of  FIG. 13D , text prompt  1332  provides written instruction to the user to turn their head to the right (e.g., in the same direction indicated by the arrow element in visual prompt  1328 ). In some examples, device  1300  also issues audio output  1334  corresponding to visual movement prompt  1328  and/or text prompt  1328 . For example, if a screen reader functionality is enabled, audio output  1334  is a verbal description of the requested movement (e.g., an auditory recitation of text prompt  1332 ). In some examples, audio output  1334  is issued instead of or in addition to visual movement prompt  1328  and/or text prompt  1332 . In some examples, device  1300  also issues tactile output  1336  (e.g., a vibration, e.g., instead of or in addition to audio output  1334 ). In some examples, audio output  1334  and/or tactile output  1336  coincides with movement (e.g., an animation) of visual movement prompt  1328 , as described in more detail below. 
     In some examples, device  1300  displays an animation of visual movement prompt  1328  to provide further indication of the requested movement. In the example of  FIGS. 13D-13E , device  1300  transitions display of the arrow element of visual prompt  1328  in the requested direction of movement (e.g., to the right). In some examples, visual prompt  1328  also includes one or more lines (e.g., arcs) that extend over a central portion of user facial image  1326 . In some examples, these lines appear extend out of the plane of display  1302  into a virtual z-dimension (e.g., normal to the display). In the examples of  FIG. 13D-13E , device  1300  rotates the arc in the requested direction of movement (e.g., to the right) to provide visual demonstration the requested movement in three dimensions that accompanies movement of the arrow element. In some examples, while displaying the animation of visual movement prompt  1328 , device  1300  continues to display text prompt  1332 . In some examples, device  1300  issues audio output  1334  and/or tactile output  1336  while displaying the animation such that the outputs correspond to movement of the arrow and/or arc element of visual prompt  1328 . 
     In some examples, while displaying visual movement prompt  1328  and/or text prompt  1332 , device  1300  detects (e.g., for a second time) that the orientation of the user&#39;s face with respect to biometric sensor  1303  has not changed for a predetermined amount of time. In response, device  1300  issues a tactile output (e.g., tactile output  1338  shown in  FIG. 13E ). In some examples, tactile output  1338  is generated as an error to indicate that facial enrollment has stopped (e.g., because the user has not moved his or her face for a predetermined amount of time). 
     In the example of  FIG. 13F , in response to detecting that the orientation of the user&#39;s face has not changed for the predetermined amount of time, device  1300  displays a second set of enrollment hints that prompt the user to move his or her face in a different direction. In the example of  FIG. 13F , device  1300  displays second visual movement prompt  1340 . Second visual movement prompt  1340  has similar visual characteristics to visual movement prompt  1328 , but corresponds to a second, different requested direction of movement than visual prompt  1328  (e.g., up instead of right). For example, second visual movement prompt  1340  includes a second arrow element that points in a different direction than the arrow element of visual movement prompt  1328  (e.g., up instead of right). Additionally, in some examples, second visual movement prompt  1340  includes an arc element similar to that of visual prompt  1328 , which is used to provide a visual demonstration of the requested second direction of movement as described below with respect to  FIGS. 13F and 13G . 
     In some examples, the second set of enrollment hints includes text prompt  1342  providing written instructions to user that match visual movement prompt  1340 . In the example of  FIG. 13F , text prompt  1342  provides written instruction to the user to tilt their head to the upwards (e.g., in the second direction indicated by the arrow element of second visual prompt  1340 ). In the example of  FIG. 13F , device  1300  also issues audio output  1344  corresponding to second visual movement prompt  1340  and/or text prompt  1342 . For example, if the screen reader functionality is enabled, audio output  1344  is a verbal description of the requested movement (e.g., an auditory recitation of text prompt  1342 ). In some examples, device  1300  issues tactile output  1346  (e.g., a vibration, e.g., instead of or in addition to audio output  1334 ). 
     As illustrated in  FIGS. 13F-13G , in some examples, device  1300  displays an animation of visual movement prompt  1340  to provide further indication of the second requested direction of movement. In the example of  FIGS. 13F-13G , device  1300  transitions display of the arrow element of second visual prompt  1340  in the second requested direction of movement (e.g., upward). In the examples of  FIG. 13F-13G , the animation also rotates the arc element of second visual prompt  1340  in the second requested direction of movement (e.g., upwards into the plane of the display) to provide visual demonstration the requested movement in three dimensions that accompanies movement of the arrow element. In some examples, while displaying the animation of visual movement prompt  1340 , device  1300  continues to display text prompt  1340 . In some examples, device  1300  issues audio output  1344  and/or tactile output  1346  while displaying the animation such that the outputs correspond to movement of the arrow and/or arc element of visual prompt  1340 . 
     Turning now to  FIG. 13H , device  1300  detects a change in orientation of the user&#39;s face relative to biometric sensor  1303  (e.g., the user is tilting or has tilted his or her face upwards, the second requested direction of movement). In response to detecting the change in orientation, device displays (e.g., for a second time) face enrollment interface  1304 , described above with respect to  FIG. 13A . In the example of  FIG. 13H , device  1300  has updated (e.g., displayed movement of) user facial image  1306  to reflect the change in orientation of the user&#39;s face. In some examples, orientation guide  1308  tracks the movement (e.g., moves along with) user facial image  1306  to visually emphasize tilting and rotational movements of the user&#39;s face in three-dimensions. For example, the center (e.g., intersection) of orientation guide  1308  is optionally positioned at a central point on user facial image  1306  and moves along with it. In some examples, device  1300  also adjusts the curvature of the lines comprising orientation guide  1308  to give the appearance of three-dimensional rotation (e.g., upwards into the plane of the display). In some examples, device  1100  emphasizes orientation guide  1108  while it is in motion (e.g., while the orientation of the user&#39;s face is changing). For example, device  1300  optionally darkens orientation guide  1308  while it is in motion and/or display a fading trail as it tracks movement of the user&#39;s face. In this case, device  1300  optionally reduces this emphasis on orientation guide  1308  relative to user facial image  1306  when the user&#39;s face is not moving. 
     As shown in the example of  FIG. 13G , in response to detecting that the user&#39;s face is oriented towards progress meter portion  1348  (e.g., a set of one or more progress elements such as  1310   a ,  1310   b ,  1310   c ), device  1300  updates the display of the progress elements in meter portion  1348  to an “enrolling” state by changing the appearance of the progress elements in meter portion  1348 . For example, device  1300  optionally enlarges and/or change the color of progress elements in meter portion  1348  while user&#39;s face is oriented towards meter portion  1348 . In some examples, device  1300  elongates the progress ticks and changes their color from grey to blue when updating progress elements to the “enrolling” state. In some examples, changing the display of progress elements to the “enrolling” state in this manner indicates that device  1300  is capturing (e.g., enrolling) facial imaging data for the angular view corresponding to the current orientation of the user&#39;s face. In the example of  FIG. 13G , device  1300  maintains progress elements in progress meter  1310  (e.g., progress elements that are not part of meter portion  1348 ) in an unenrolled state (e.g., greyed out) to indicate that device  1300  has not yet detected the user&#39;s face in orientations corresponding to those progress elements. In some examples, the display of meter portion  1348  is updated in this manner only if the user&#39;s face is sufficiently rotated towards meter portion  1348  (e.g., if the user&#39;s face is rotated by at least a threshold amount or angle). 
     Turning now to the example of  FIG. 13I , device  1300  detects that the user&#39;s face is no longer in the orientation corresponding to meter portion  1348  (e.g., the user has tilted their head downwards back to a neutral position). In response, device  1300  changes the appearance of progress elements in meter portion  1348  a second time to an “enrolled” state. In the example of  FIG. 13I , device  1300  updates the display of progress ticks in portion  1348  from the elongated “enrolling” state by shortening the progress ticks and changing their color a second time. For example, progress elements in the “enrolled” state are the same length and/or size of progress elements in the “unenrolled” state, but are displayed in green to indicate that the corresponding portion of the user&#39;s face (e.g., the angular view captured in  FIG. 13J ) has been successfully enrolled as described above in connection with  FIG. 11J . In the example of  FIG. 13J , device  1300  maintains other progress elements in enrollment progress meter  1310  in an unenrolled state to indicate that the device has not yet detected the user&#39;s face in an orientation corresponding to those progress elements. In response to detecting the change in facial orientation, device  1300  also moves orientation guide  1308  such that it tracks the movement of user facial image  1306  in the digital viewfinder. 
     Turning now to the example of  FIG. 13J , after detecting the change in orientation depicted in  FIG. 13I , the device detects (e.g., for a second time) that the orientation of the user&#39;s face relative to biometric sensor  1303  has not changed for a predetermined period of time. In response, device  1300  displays hint-enabled enrollment interface  1350 . In some examples, hint-enabled enrollment interface  1350  is displayed automatically. In some examples, hint-enabled enrollment interface  1350  is displayed in response to detecting activation (e.g., selection) of an affordance (e.g., similar to yes affordance  1318  on hint-enablement interface  1314 ). In some examples, hint-enabled enrollment interface  1350  and its components (e.g., user facial representation  1352 , enrollment progress meter  1354 , visual movement prompt  1356 , and text prompt  1358 ) have the same visual characteristics as described above with respect to hint-enablement interface  1324  in  FIG. 13D . In the example of  FIG. 13J , however, device  1300  displays progress elements in meter portion  1360  of enrollment progress meter  1354  in the “enrolled” state, since the facial orientation corresponding to the same portion of progress meter  1330  has already been enrolled (e.g., in the manner of  FIG. 13H ). 
     In the example of  FIGS. 13J-13K , device  1300  displays an animation of visual movement prompt  1356  that prompts the user to move his or her face into an orientation that has not yet been enrolled. For example, the animation of visual prompt  1356  prompts the user to move his or her face in the first requested direction (e.g., to the right). The animation of visual movement prompt  1356  has similar or identical characteristics to the animation of visual movement prompt  1328  described above with respect to  FIGS. 13D-13E . For example, device  1300  transitions display of the arrow element of visual prompt  1356  in a requested direction of movement corresponding to a facial orientation that has not yet been enrolled (e.g., to the right). In the examples of  FIG. 13J-13K , the animation also rotates the arc element of visual prompt  1356  in the requested direction of movement (e.g., to the right) to provide visual demonstration the requested movement in three dimensions that accompanies movement of the arrow element. In some examples, while displaying the animation of visual movement prompt  1356 , device  1300  continues to display text prompt  1358 , which provides a written description of the requested movement. In some examples, device  1300  issues audio output  1362  and/or tactile output  1364  while displaying the animation such that the outputs correspond to movement of the arrow and/or arc element of visual prompt  1340 . 
     Turning to the example of  FIG. 13L , device  1300  has detected (e.g., for a third time) that the orientation of the user&#39;s face with respect to biometric sensor  1303  has not changed for a predetermined amount of time. In the example of  FIG. 13L , in response to detecting little to no change in the user&#39;s facial orientation, device  1300  displays accessibility enrollment interface  1368 . In some examples, accessibility enrollment interface includes user facial image  1370 , which optionally has similar or identical characteristics to user facial image  1308 . In particular, user facial image  1370 , optionally, is a live preview of image data captured by biometric sensor  1303 . In the example of  FIG. 13L , accessibility enrollment interface  1368  includes enrollment progress meter  1372 , which is, optionally, displayed surrounding user facial image  1370 . In some examples, the display of meter portion  1370  indicates orientations and/or portions of the user&#39;s face that have been previously enrolled (e.g., while device  1300  displayed enrollment interface  1304  or hint enabled enrollment interfaces  1324  and/or  1350  during a previous stage of enrollment). For example, device  1300  displays progress elements in portion  1374  of progress meter  1370  (which corresponds to meter portions  1348  and/or  1360 ). In the example of  FIG. 13L , accessibility enrollment interface  1368  also includes accessibility options affordance  1378 . In some examples, activation of accessibility options affordance  1378  allows the user to set up biometric (e.g., face) authentication with only a partial scan (e.g., after enrolling only a subset of the face orientations or portions that are be enrolled during a full scan). 
     In the example of  FIG. 13M , device  1300  detects activation (e.g., selection) of accessibility options affordance  1378  (e.g., by user input  1380 ). In response to detecting activation of accessibility options affordance  1378 , device  1300  displays completion affordance  1382  on accessibility enrollment interface as illustrated in  FIG. 13N . In some examples, activation of the completion affordance allows the device to proceed using only a partial scan of their facial features. 
     In the example of  FIG. 13O , device  1300  detects activation (e.g., selection) of completion affordance  1382  by way of user input  1384 . In response to detecting activation of completion affordance, device  1300  displays partial scan acknowledgement interface  1386  as illustrated in  FIG. 13P . Partial scan acknowledgement interface includes user facial image  1387 , which, optionally, has some or all of the visual characteristics of user facial image  1370 . Since a portion of the user&#39;s face has been successfully enrolled, device  1300  also displays enrollment success indicator  1388 , for example, proximate to and/or surrounding user facial image  1387 . In the example of  FIG. 13P , partial scan acknowledgement interface  1386  includes text prompt  1389 , which provides written indication that image data corresponding to at least a portion of the user&#39;s face has been successfully captured and enrolled. In the example of  FIG. 13P , device  1300  displays enrollment completion affordance  1390 . 
     In the example of  FIG. 13Q , device  1300  detects activation (e.g., selection) of enrollment completion affordance  1390  by way of user input  1392 . In some examples, in response to detecting activation of enrollment completion affordance, device  1300  enrolls image data of one or more angular views (e.g., orientations) of the user&#39;s face captured during the enrollment process described above. Optionally, device  1300  issues tactile output  1393  to acknowledge completion of the enrollment process. In some examples, tactile output  1393  is the same tactile output that is issued in response to successful biometric authorization at device  1300 . In the example of  FIG. 13Q , device  1300  replaces the display of success indicator  1388  with partial enrollment indicator  1391  proximate to facial image  1387 , which visually indicates orientations of the user&#39;s face that have been successfully enrolled. In some examples, the size (e.g., arc length) and position of partial enrollment indicator  1391  corresponds to portions of the progress meter (e.g.,  1310 ,  1354 ,  1372 ) that were transitioned to the “enrolled” state during enrollment. In the example of  FIG. 13Q , device  1300  displays partial enrollment indicator  1391  in a similar position as meter portion  1374  to indicate one or more facial orientations corresponding to meter portion  1374  were successfully enrolled. 
     In the example of  FIG. 13R , in response to detecting activation (e.g., selection) of enrollment completion affordance  1390  (e.g., by user input  1392 ), device  1300  displays enrollment completion interface  1394 . As shown in  FIG. 13R , enrollment completion interface  1394  includes biometric authentication glyph  1395 . For example, biometric authentication glyph  1395  optionally is a line drawing of all or part of a face (e.g., a stylized face graphic). In the example of  FIG. 13R , enrollment completion interface  1394  also includes text prompt  1396  indicating that the enrollment process is complete and face authentication at the device is set-up and/or enabled. In some examples, enrollment completion interface  1394  also includes completion affordance  1397 , activation of which causes device  1300  to exit face authentication set-up. In some examples, enrollment completion interface  1394  does not include facial image  1387 . 
       FIG. 14  is a flow diagram illustrating a method for providing hints to effectively enroll a biometric feature on an electronic device in accordance with some examples. Method  1400  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1300 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric features by the one or more biometric sensors. Some operations in method  2000  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  1400  provides an intuitive way to provide hints for effectively enrolling a biometric feature on an electronic device. The method reduces the cognitive burden on a user for enrolling a biometric feature on the device, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to enroll a biometric feature faster and more efficiently conserves power and increases the time between battery charges 
     The device displays ( 1402 ), on the display, a biometric enrollment user interface (e.g.,  1304 ,  1324 ) for enrolling a biometric feature (e.g., user face, fingerprint, iris, handprint, or other physical biometric feature that can be used to distinguish one person from another person). Displaying the biometric enrollment user interface includes displaying a representation of the biometric feature (e.g.,  1306 ,  1326 , a representation of the head of a user of the device). The appearance of the representation of the biometric feature changes ( 1404 ) as the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1303 ) changes. For example, the orientation of the biometric feature relative to the one or more biometric sensors optionally is based on the alignment of a face of a user in image data captured by the one or more cameras (e.g., camera data that includes the user&#39;s head positioned in the field of view of one or more of the cameras). Displaying a preview of the image captured by the biometric sensors provides the user with feedback about the position and orientation of his or her biometric features relative to the biometric sensors of the device, enabling the user to properly align his or her biometric features with the sensors more quickly and efficiently in order to proper enrollment the biometric features. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     While displaying the biometric enrollment user interface, the device detects ( 1406 ) that enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature. 
     In some examples, the enrollment-prompt criteria include ( 1408 ) a requirement that the biometric feature moves less than a first threshold amount for at least a first threshold time period (as determined by the one or more biometric sensors). Automatically enabling enrollment hints after detecting little to no movement of the user&#39;s biometric feature reduces the time required to complete the enrollment process, since a user who is struggling to execute the required movements quickly and automatically receives instructions on how to proceed with the enrollment process. Performing an optimized set of operations when a set of conditions have been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In response to detecting that the enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature, the device outputs ( 1410 ) a respective prompt (e.g.,  1328 ,  1332 ,  1334 ,  1336 ,  1340 ,  1342 ,  1344 ,  1346 , e.g., a visual, audible, and/or tactile prompt) to move the biometric feature in a respective manner. The respective prompt is selected ( 1412 ) based on an enrollment state of one or more portions of the biometric feature (e.g., whether a first portion and/or a second portion of the biometric feature have been enrolled). In particular, in accordance with a determination that the enrollment-prompt criteria have been met with respect to a first portion of the biometric feature that can be enrolled by moving the biometric feature in a first manner, the device outputs ( 1424 ) a prompt (e.g.,  1328 ,  1332 ,  1334 ,  1336 ) to move the biometric feature in the first manner. In accordance with a determination that the enrollment-prompt criteria have been met with respect to a second portion of the biometric feature that can be enrolled by moving the biometric feature in a second manner, different from the first manner, outputting the respective prompt includes outputting ( 1426 ) a prompt (e.g.,  1340 ,  1342 ,  1344 ,  1346 ) to move the biometric feature in the second manner. Providing visual and/or auditory prompts to move the biometric feature in a particular direction allows the user to quickly and intuitively realize how to position the biometric feature such that a corresponding portion can enrolled. These prompts allow the user the move the biometric feature though the range of orientations required for the enrollment process more quickly and efficiently than they would otherwise. Providing improved visual and/or auditory feedback with instructions on proper movements of the biometric feature therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in accordance with a determination that auditory prompt criteria are met (e.g., determining whether screen reader functionality of the device is enabled), the device outputs an auditory prompt (e.g.,  1334 ) to move the biometric feature in the first manner (e.g., instead of or in addition to one or more visual prompts). In some examples, in accordance with a determination that auditory prompt criteria are not met, the device provides the user with an option to enable auditory prompts for the biometric enrollment. For example, the device displays an affordance (e.g.,  1318 ), which when selected by a user, causes auditory prompts to be enabled, or provide an audio prompt (e.g.,  1334 ,  1344 ) that describes steps for enabling auditory prompts for the biometric enrollment. Providing auditory instructions to move the biometric feature in a particular direction allows the user to quickly and intuitively realize how to position the biometric feature such that a corresponding portion can enrolled. These prompts allow the user the move the biometric feature though the series of orientations required for the enrollment process more quickly and efficiently than they would otherwise. Providing improved auditory feedback with instructions on proper movements of the biometric feature therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently 
     In some examples, the device outputs the respective prompt (e.g.,  1328 ,  1332 ,  1334 ,  1336 ,  1340 ,  1342 ,  1344 ,  1346 , e.g., a visual, audible, and/or tactile prompt) before any portion of the biometric feature has been enrolled. For example, the respective prompt optionally indicates ( 1422 ) that the user should start tilting their head to begin the enrollment process. 
     In some examples, the device outputs the respective prompt (e.g.,  1328 ,  1332 ,  1334 ,  1336 ,  1340 ,  1342 ,  1344 ,  1346 , e.g., a visual, audible, and/or tactile prompt) after at least a portion of the biometric feature has been enrolled. For example, the prompt optionally indicates that the user should continue tilting their head to continue the enrollment process. Automatically issuing prompts to move the biometric feature in a second direction after the user has moved the biometric feature in the first direction allows the user to quickly and intuitively understand how to continue moving the biometric feature to proceed with the enrollment process. Assisting the user in understanding how to execute the required movements of the biometric feature in quick succession reduces the amount of time required to complete enrollment of the biometric feature. Thus, performing an optimized set of operations when a set of conditions have been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device outputs a tactile output (e.g.,  1336 ,  1346 ). In some examples, the tactile output is accompanied by an audible output (e.g.,  1334 ,  1344 ). In some examples, the tactile output and/or the audio output are generated to coincide with movement of a visual prompt (e.g.,  1328 ,  1340 ). For example, the tactile outputs optionally correspond to movement of an arrow or arc (e.g., arrow element and arc element in  1328  and/or  1340 ) in a direction in which the user is being prompted to move the biometric feature. 
     In some examples, the respective prompt includes a tactile output (e.g.,  1338 ,  1366 ) that is used to indicate a failed biometric authentication with the device. For example, the tactile output that is generated as an error when biometric enrollment has stopped due to a failure to change the orientation of the biometric feature relative to the one or more biometric sensors is the same as the tactile output that is used to indicate a failed biometric authentication. 
     In some examples, the device overlays a visual prompt (e.g.,  1328 ,  1340 ,  1356 ) on the representation of the biometric feature. For example, the visual prompt optionally is an arrow indicating the respective manner (direction) in which to move the biometric feature (such as up, down, to the left, to the right, at a diagonal angle between those directions). In some examples, the visual prompt is partially transparent. Displaying visual prompt such as an arrow element in the requested direction of movement allows the user to quickly understand how to move the biometric feature such that a portion of the feature corresponding to the requested direction can be properly enrolled. This allows the user execute the requested movement more quickly and efficiently, reducing the amount of time required by the enrollment process. Providing improved visual prompting that illustrates proper movements of the biometric feature therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device displays ( 1414 ) an animation prompt (e.g., animation of  1328 ,  1340 , or  1356  described with respect to  FIG. 13D-13E, 13F-13G , or  13 J- 13 K) to move the biometric feature in the respective manner. For example, the device optionally displays an animation prompting movement in a first manner (e.g., animation of  1328  shown in  FIGS. 13D-13E ) with respect to the first portion of the biometric feature and displays an animation prompting movement in a second manner (e.g., animation of  1340  in  FIGS. 13F-13G ) with respect to a second portion of the biometric feature. In some examples, displaying the animation prompt includes displaying ( 1416 ) an arrow element (e.g., arrow element of  1328 ,  1340 , or  1356 ) indicating the respective manner in which to move the biometric feature. Displaying an animation that intuitively illustrates the requested direction of movement allows the user to quickly understand how to move the biometric feature such that a portion of the feature corresponding to the requested direction can be properly enrolled. This allows the user execute the requested movement more quickly and efficiently, reducing the amount of time required by the enrollment process. Providing improved visual feedback with intuitive illustrations of proper movements of the biometric feature therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the device outputs ( 1420 ) at least one of a tactile output (e.g.,  1336 ,  1346 ,  1364 ) or an auditory output (e.g.,  1334 ,  1344 , or  1362 ) corresponding to the animation. For example, the animation optionally zooms in and out on biometric feature. Alternatively and/or additionally, one or more elements of enrollment user interface (e.g.,  1324 ,  1350 ) optionally temporarily changes state. In general, the tactile output syncs with the animation. Providing tactile and/or audio outputs that accompany a visual illustration of the requested movement allows the user to quickly understand how to move the biometric feature such that a portion of the feature corresponding to the requested direction can be properly enrolled. This allows the user execute the requested movement more quickly and efficiently, reducing the amount of time required by the enrollment process. Providing improved tactile and/or auditory feedback accompanying an animation therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the first manner of movement includes rotation about an axis parallel to the display (e.g., in the plane of display  1302 ) and the second manner of movement includes rotation about an axis parallel to the display. In this case, the animation prompt (e.g., animation of  1328 ,  1340 , or  1356  described with respect to  FIG. 13D-13E, 13F-13G , or  13 J- 13 K) includes ( 1418 ) simulated rotation of a user interface element (e.g., arc element of  1328 ,  1340 , or  1356 ) about the axis parallel to the display. For example, if the user is being prompted to rotate the biometric feature clockwise about an axis parallel to the display, the animation optionally includes movement of a user interface element clockwise about an axis parallel to the display. Likewise, if the user is being prompted to rotate the biometric feature counter-clockwise about an axis parallel to the display, the animation optionally includes movement of a user interface element counter-clockwise about an axis parallel to the display. Displaying simulated rotation of an orientation element to illustrate the requested movement allows the user to quickly understand how to move the biometric feature such that a portion of the feature corresponding to the requested direction can be properly enrolled. This allows the user execute the requested movement more quickly and efficiently, reducing the amount of time required by the enrollment process. Providing improved visual feedback with intuitive illustrations of proper movements of the biometric feature therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the biometric enrollment user interface includes an orientation guide (e.g.,  1308 ) that is overlaid on the representation of the biometric feature (e.g.,  1306 ) and tilts in different directions as the representation of the biometric feature tilts in different directions (e.g., as described above with reference to method  1200 ). In this example, in accordance with a determination that the enrollment-prompt criteria have been met with respect to the first portion of the biometric feature that can be enrolled by moving the biometric feature in the first manner, the animation prompt (e.g., animation of  1328  or  1356  described with respect to  FIG. 13D-13E or 13J-13K ) includes movement of a portion of the orientation guide (e.g., the vertical component of  1308 ) in a direction that the orientation guide would move if the biometric feature moved in the first manner. Displaying and/or rotating the orientation guide overlaid on the representation of the biometric feature provides the user with feedback about the orientation of his or her biometric features relative to the biometric sensors of the device in three-dimensional space, enabling the user more quickly move the biometric feature through the required range of orientations during the enrollment process. Providing improved visual feedback regarding the orientation of the biometric feature to the user therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     Likewise, in accordance with a determination that the enrollment-prompt criteria have been met with respect to the second portion of the biometric feature that can be enrolled by moving the biometric feature in the second manner, the animation prompt (e.g., animation of  1340  described with respect to  FIGS. 13F-13G ) includes movement of a portion of the orientation guide in a direction that the orientation guide would move if the biometric feature moved in the second manner. In some examples, the orientation guide includes a first portion (e.g., the horizontal component of  1308 , e.g., a first arc) and a second portion (e.g., the horizontal component of  1308 , e.g., second arc that crosses the first arc) and the animation prompt (e.g., animation of  1340  shown in  FIGS. 13F-13G ) includes moving the first portion of the orientation guide without moving the second portion, or moving the second portion without moving the first portion. In some examples if the first portion of the orientation guide is moving, then the second portion ceases to be displayed. Similarly, if the second portion is moving then the first portion ceases to be displayed. In some examples, if enrollment is needed for a portion of the biometric feature that is not visible when the feature is tilted up, down, to the left, or to the right, the animation moves in a diagonal direction to prompt the user to tilt the biometric feature in the diagonal direction. 
     In some examples, after outputting a respective prompt (e.g.,  1328 ,  1332 ,  1334 ,  1336 ,  1340 ,  1342 ,  1344 ,  1346 ) to move the biometric feature in a respective manner, and in response to detecting the movement of the biometric feature, the device enrolls the respective portion of the biometric feature. Optionally, the device updates a progress indicator (e.g.,  1310 ,  1330 ) as described in method  1200 . While enrolling the respective portion of the biometric feature, the device optionally ceases to provide the prompts. Updating the progress indicator during enrollment in this manner encourages the user to look at the display of the electronic device during the enrollment to improve the ability to detect when gaze is directed at the display, and thus whether or not the user is paying attention to the device. Encouraging the user to look at the display of the electronic device enhances the operability of the device and makes the user-device interface more efficient (e.g., by ensuring that the gaze of the user is directed at the display and thereby ensuring that the biometric feature of the user is properly enrolled) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, after enrolling the respective portion of the biometric feature, the device determines that enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature. In response to determining that enrollment-prompt criteria have been met with respect to one or more portions of the biometric feature, (e.g., the user stops responding during enrollment for a threshold period of time), the device outputs another respective prompt (e.g.,  1356 ,  1358 ,  1362 ,  1364 ) to move the biometric feature in a respective manner determined based on the one or more portions of the biometric feature for which the enrollment-prompt criteria have been met. For example, the device starts prompting the user to change the orientation of the biometric feature with respect to the one or more biometric sensors to enroll the portions of the biometric feature that have not yet been enrolled. In some examples the prompts have similar characteristics to the other prompts described above. In some examples, the prompts progress in a similar manner as the prompts described above. In some examples, a first prompt (e.g.,  1356 ,  1358 ,  1362 ,  1364 ), is provided in a first direction after the first time period with little or no movement of the biometric feature relative to the one or more biometric sensors, and a second prompt is provided in a second direction after the second time period (longer than the first time period) with little or no movement of the biometric feature relative to the one or more biometric sensors, and an option (e.g.,  1382 ,  1390 ) to complete the biometric enrollment without enrolling all portions of the biometric feature is provided after the third time period (longer than the first time period) with little or no movement of the biometric feature relative to the biometric sensors. Automatically providing prompts to move the biometric feature in a different direction after detecting little to no movement of the biometric feature assists a user who is struggling or unable to execute the movement in the first direction by quickly and automatically providing instructions on how to proceed with the enrollment process. Performing an optimized set of operations when a set of conditions have been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, after outputting a respective prompt (e.g., (e.g.,  1328 ,  1332 ,  1334 ,  1336 ,  1340 ,  1342 ,  1344 ,  1346 ,  1356 ,  1358 ,  1362 ,  1364 ) to move the biometric feature in a respective manner, in accordance with a determination that accessibility prompt criteria have been met, the device displays ( 1428 ) an option (e.g.,  1378 ) to proceed with the enrollment without further changes in the orientation of the biometric feature relative to the one or more biometric sensors (e.g.,  1303 ). The accessibility prompt criteria include ( 1430 ) a requirement that the orientation of the biometric feature relative to the one or more biometric sensors has changed less than a predetermined amount for a respective period of time. For example, the biometric feature of the user has not been detected as moving for a threshold period of time after providing the second prompt (e.g.,  1340 ,  1342 ,  1344 ,  1346 ). In this case, an accessibility affordance (e.g.,  1378 ) is displayed, and user optionally selects (e.g.,  1380 ) the accessibility affordance. In other words, the user can approve use of biometric feature authentication for a view of the biometric feature from a range of orientations that is less than the available range of orientations. In some examples, the respective period of time is greater than the second period of time. For example, after a delay with little or not movement of the biometric feature relative to the one or more biometric sensors (e.g.,  1303 ), the device first prompts (e.g., with  1328 ,  1332 ,  1334 ,  1336 ) movement of the biometric feature in a first direction; then after a delay with little or no movement, the device prompts (e.g., with  1340 ,  1342 ,  1344 ,  1346 ) movement of the biometric feature in a second direction; then after an additional delay with little or no movement, the device provides an option (e.g.,  1378 ) to proceed with enrollment without additional movement of the biometric feature relative to the one or more biometric sensors. In some examples, the accessibility prompt (e.g.,  1378 ) is displayed after enough of the biometric feature has been captured to ensure secure authentication with at least a portion of the biometric feature (e.g., as soon as one angle of the face has been captured and enrolled a user with limited mobility can select the accessibility option to enroll the biometric feature using just the enrolled angles). 
     In some examples, the device detects ( 1432 ) selection of the option to proceed with the enrollment without further changes in the orientation of the biometric feature relative to the one or more biometric sensors. For example, in some examples, the device receives a user input (e.g.,  1382 ) indicating a selection of an affordance (e.g.,  1380 ) of the accessibility interface (e.g.,  1368 ) for confirming enrollment of the biometric data. In response to detecting selection of the option to proceed with the enrollment without further changes in the orientation of the biometric feature relative to the one or more biometric sensors ( 1434 ), the device forgoes ( 1436 ) (e.g., skips) one or more steps in the biometric enrollment. For example, the device skips display of a second biometric enrollment user interface (e.g., second enrollment interface  1138  in  FIG. 11H ) that would be displayed in a standard enrollment process where the biometric feature changes orientation as prompted by the device (e.g., there is no second enrollment flow if the user enrolls via the accessibility interface, as described with respect to method of  1200 ). 
     In some examples, in response to selection of the option to proceed with the enrollment without further changes in the orientation of the biometric feature relative to the one or more biometric sensors ( 1434 ), the device displays ( 1438 ) an indication that enrollment of the biometric feature is complete that includes information about which portions of the biometric feature have been enrolled (e.g.,  1391  and  1389 ). In some examples, the device displays an affordance (e.g.,  1390 ), which when selected, confirms partial enrollment of the biometric feature. 
     In some examples, in response to detecting selection of the option to proceed with the enrollment without further changes in the orientation of the biometric feature relative to the one or more biometric sensors, the device outputs a tactile output (e.g.,  1393 ) that is used to indicate successful biometric authentication with the biometric feature once the biometric feature has been enrolled. For example, the tactile output that is generated when biometric enrollment is complete is optionally the same tactile output that is used to indicate successful authentication with the biometric feature. 
     Note that details of the processes described above with respect to method  1400  (e.g.,  FIGS. 14A-14B ) are also applicable in an analogous manner to the methods described herein. For example, method  1400  optionally includes one or more of the characteristics of the various methods described herein with reference to methods  800 ,  1000 ,  1200 ,  1600 ,  1800 ,  2000 ,  2200 ,  2500 , and  2700 . For example, the accessibility interface described in method  1000  can be applied with respect to the accessibility enrollment interface (e.g.,  1368 ). For another example, the orientation guide as described in method  1200  can be applied with respect to the orientation guide (e.g.,  1308 ). For brevity, these details are not repeated below. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 14A-14B  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, displaying operation  1402 , detecting operation  1406 , outputting operation  1408 , outputting operation  1412 , and outputting operation  1414 , are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 15A-15T  illustrate exemplary user interfaces for biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary example of the user interfaces illustrated in  FIGS. 15A-15T  are used to illustrate the processes described below, including the processes in  FIGS. 16A-16E . 
       FIG. 15A  illustrates an electronic device  1500  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary example illustrated in  FIGS. 15A-15T , electronic device  1500  is a smartphone. In other examples, electronic device  1500  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  1500  has a display  1502 , one or more input devices (e.g., touchscreen of display  1502 , a button  1504 , a microphone (not shown)), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  1503 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  1503  are the one or more biometric sensors  703 . n some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 15A , the electronic device  1500  displays, on display  1502 , an application interface  1506  including a log-in affordance  1508 . In the example of  FIG. 15A , the application is a browser displaying, in the interface of the browser, a website (e.g., onlinestore.com). In  FIG. 15B , while displaying the application interface  1506 , the electronic device  1500  detects activation of the log-in affordance  1508 . As shown, the activation is a tap gesture  1510  on log-in affordance  1508 . 
     In  FIG. 15C , in response to detecting the activation of the log-in affordance  1508 , the electronic device  1500  initiates biometric authentication. In some examples, initiating biometric authentication includes obtaining (e.g., capturing with the one or more biometric sensors) data corresponding to at least a portion of the biometric feature of a user (e.g., a user&#39;s face). In  FIG. 15C , initiating biometric authentication further includes displaying a biometric authentication interface  1512  having a biometric authentication glyph  1514 . In the example of  FIG. 15C , the biometric authentication glyph  1514  is a simulation of a representation of the biometric feature (e.g., a face). As seen in  15 C, the biometric authentication interface  1512  is overlaid on at least a portion of the application interface  1506 . In some examples, the biometric authentication interface is an operating system level interface (e.g., an interface generated by an operating system of the device), and the application interface  1506  is an application-level interface (e.g., a user interface generated by a third-party application that is separate from the operating system of the device). 
     While in some examples, the electronic device  1500  initiates biometric authentication in response to activation of a log-in affordance of an application, in other examples, the electronic device  1500  initiates (e.g., automatically begins) biometric authentication in response to loading the application and/or the application interface  1506 . The application interface is displayed, for instance, in response to loading the application (e.g., by selecting an icon associated with the application on a home screen of the electronic device  1500 ). 
     In some examples, including the example of  FIG. 15C , the biometric authentication interface is partially translucent. In some examples, display (e.g., a visual characteristic) of the biometric authentication interface  1512  is based on the application interface  1506 . By way of example, one or more colors of the biometric authentication interface  1512  are based on one or more colors of the application interface  1506 . With reference to  FIG. 15C , the electronic device  1500  displays an application interface  1506  having a first color scheme, and the biometric authentication interface  1512  is displayed based on the first color scheme (e.g., is displayed using colors that contrast with the first color scheme). With reference to  FIG. 15D , the electronic device  1500  displays an application interface  1507  having a second color scheme different than the first color scheme, and the biometric authentication interface  1512  is displayed based on the color scheme. Displaying the biometric authentication interface  1512  in this manner allows for the biometric authentication interface  1512  to be easily recognized and viewed by a user when overlaid on an application interface. 
     In response to initiating biometric authentication, the electronic device  1500  captures and processes (e.g., analyzes) the biometric data to determine, based on the biometric data, whether the biometric feature (or a portion thereof) satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template). In some examples, in response to obtaining the biometric data, the electronic device  1500  displays a biometric authentication animation that, for instance, includes changing the size of a biometric authentication glyph. In some examples, while the electronic device processes the biometric data, the electronic device displays (e.g., replaces display of the biometric authentication glyph  1514  with) one or more biometric authentication glyphs and/or biometric authentication animations to indicate that the biometric data is being processed. 
     By way of example, in  FIG. 15E , the electronic device displays the biometric authentication glyph  1514  in response to initiation of biometric authentication. With reference to  FIGS. 15F-G , once the electronic device  1500  has obtained biometric data (e.g., obtained sufficient biometric data), the electronic device  1500  displays a biometric authentication animation including the biometric authentication glyphs  1515  ( FIG. 15F ) and  1516  ( FIG. 15G ), which serve as a portion of animation in which the biometric authentication glyph  1514  is replaced by (e.g., transitioned to) the biometric authentication glyph  1517  ( FIG. 15H ). With reference to  FIG. 15H , the electronic device  1500  displays the biometric authentication glyph  1517  to indicate that the biometric data is being processed. In some examples, the biometric authentication glyph  1517  includes a plurality of rings, which rotate spherically, for instance, while displayed. 
     In  FIG. 15I , the electronic device  1500  determines that the biometric feature satisfies the biometric authentication criteria. In response, the electronic device displays (e.g., replaces display of the biometric authentication glyph  1517  with) a biometric authentication glyph  1518  in the biometric authentication interface  1512 , indicating that the biometric authentication was successful. Additionally or alternatively, the electronic device outputs a tactile output  1520  indicating the biometric authentication was successful. After indicating the biometric authentication is successful, the electronic device  1500  provides authentication information to the application indicating that the biometric feature satisfies the biometric authentication criteria and that as a result the biometric authentication was successful. 
     As shown in  FIG. 15J , in response to the electronic device  1500  providing the authentication information indicating that the biometric feature satisfies the biometric authentication criteria, the application displays (e.g., replaces display of the application interface  1506  with) a main interface  1522 . With reference to  FIG. 15K , after a predetermined amount of time, the electronic device  1500  ceases display of the biometric authentication interface. Thereafter, the user optionally uses the application as if the user had authenticated with the application directly (e.g., using a username and password for an account associated with the application). In some examples, the electronic device  1500  ceases displaying the biometric authentication interface  1512  a predetermined amount of time after biometric authentication has completed. In other examples, the electronic device  1500  ceases displaying the biometric authentication interface  1512  a predetermined amount of time after the application has performed an operation, such as displaying an interface (e.g., main interface  1522 ). 
     Alternatively, in  FIG. 15L , the electronic device  1500  determines (e.g., after displaying the biometric authentication glyph  1517  of  FIG. 15G ) that the biometric feature does not satisfy the biometric authentication criteria. In response, the electronic device displays (e.g., replaces display of the biometric authentication glyph  1517  with) a biometric authentication glyph, such as the biometric authentication glyph  1519 , in the biometric authentication interface  1512  to indicate that the biometric authentication was unsuccessful (e.g., failed). In some examples, the biometric authentication glyph  1519  is associated with a biometric authentication failure animation. With reference to  FIGS. 15L-M , in some examples, in response to unsuccessful biometric authentication, the electronic device  1500  displays a biometric authentication failure animation in which the biometric authentication glyph  1519  moves (e.g., rotates) side-to-side to simulate a “head shake” effect and indicate that the biometric authentication was unsuccessful. Optionally, the electronic device  1500  outputs a tactile output  1526  indicating the biometric authentication was unsuccessful. In some examples, the tactile output  1526  is the same as the tactile output  1520 . In some examples, the tactile output  1526  is different than the tactile output  1520 . In some examples, the tactile output  1526  is synchronized with the biometric authentication failure animation. 
       FIGS. 15N-0  illustrate an alternative biometric failure animation in which, in response to unsuccessful biometric authentication (as determined with respect to  FIG. 15E ), the electronic device  1500  displays (e.g., replaces display of the biometric authentication glyph  1517  ( FIG. 15H ) with) the biometric authentication glyph  1514  in the biometric authentication interface  1512 . In some examples, during display of the biometric authentication failure animation, the electronic device moves the biometric authentication interface  1512  on the display  1502 . In some examples, the electronic device  1500  moves the biometric authentication interface  1512  side-to-side to simulate a “shake” effect and indicate that the biometric authentication was unsuccessful. In some examples, the electronic device moves only the biometric authentication glyph  1514 , and does not move the biometric authentication interface  1512 . In other examples, additional or alternative glyphs are used in the biometric authentication failure animation. 
     As illustrated in  FIG. 15P , in some examples, after displaying one or more biometric authentication failure animations, the electronic device displays the biometric authentication interface  1512  having the biometric authentication glyph  1514 . In this manner, the electronic device once again displays the initial biometric authentication glyph  1514 , signifying that the electronic device  1500  is enabled to perform an additional biometric authentication. In some examples, the electronic device performs an additional iteration of biometric authentication, as described with respect to at least  FIGS. 15E-N . 
     With reference to  FIG. 15Q , in some examples, in response to unsuccessful biometric authentication, the electronic device  1500  displays (e.g., replaces display of the biometric authentication interface  1512  with) a failure interface  1540 . In some examples, displaying the failure interface  1540  includes maintaining display of the biometric authentication interface  1512 . In some examples, the failure interface  1540  includes the biometric authentication glyph  1514 , an alternative authentication affordance  1544 , a retry affordance  1546 , and a cancellation affordance  1548 . In some examples, activation of the cancellation affordance  1548  causes the electronic device  1500  to cease display of the failure interface  1540 . 
     With reference to  FIG. 15R , in some examples, in response to an activation of the retry affordance  1546 , such as the tap gesture  1550 , the electronic device  1500  performs another iteration of biometric authentication. In some examples, the electronic device  1500  displays one or more biometric authentication glyphs (e.g.,  1515 - 1517 ) and/or biometric authentication animations in the failure interface  1540  to indicate progress and/or a result of the biometric authentication. With reference to  FIG. 15S , in some examples, the electronic device performs the biometric authentication only if a threshold number (e.g., 5) of failed biometric authentication attempts have not been made. In some examples, if the threshold number of failed biometric authentication attempts has been reached, the electronic device  1500  displays (e.g., replaces display of the biometric authentication glyph  1514  with) an indication  1560 , that the threshold number has been reached and that biometric authentication is not available as a result. 
     In some examples, in response to an activation of the alternative authentication affordance  1544 , such as the tap gesture  1552 , the electronic device  1500  displays (e.g., replaces display of the failure interface  1540  with) an alternative authentication interface  1562 , with which the user authenticates using an alternative form of authentication than that associated with the biometric feature (e.g., fingerprint authentication, password authentication). As illustrated in  FIG. 15T , a user optionally authenticates by entering appropriate credentials in the username field  1564  and password field  1566 , respectively. In some examples, the failure interface  1540  is an operating system level interface such that the user authenticates with the operating system of the electronic device  1500 , and the alternative authentication interface  1562  is an application-level interface such that the user authenticates with the application. 
       FIGS. 16A-16E  are a flow diagram illustrating a method for managing peer-to-peer transfers using an electronic device in accordance with some examples. Method  1600  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1500 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric feature by the one or more biometric sensors. Some operations in method  2000  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  1600  provides an intuitive way for managing authentication of biometric features. The method reduces the cognitive burden on a user for managing authentication of biometric features, thereby creating a more efficient human-machine interface and intuitive user experience. For battery-operated computing devices, enabling a user to manage authentication of biometric features faster and more efficiently conserves power and increases the time between battery charges. 
     Prior to displaying an application interface (e.g.,  1506 ) and a biometric authentication interface (e.g.,  1512 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) loads ( 1602 ) an application (e.g., A browser application as discussed with respect to  FIG. 15A ). In some examples, the application interface (e.g.,  1506 ) is an interface of a third-party application not initially installed on the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) and/or not provided by the manufacturer of the device or the manufacturer of an operating system of the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ). In some examples, the biometric authentication interface (e.g.,  1512 ) is an operating system generated asset that is not subject to the control of the application corresponding to (e.g., generating) the application interface (e.g.,  1506 ). 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) concurrently displays ( 1604 ), on the display (e.g.,  1502 ), the application interface (e.g.,  1506 ) corresponding to the application and the biometric authentication interface (e.g.,  1512 ) controlled by an operating system of the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ). Concurrently displaying the application interface and the biometric authentication interface allows the user to quickly recognize that the biometric authentication being requested is relevant to the application corresponding to the application interface, and further provides the user with more control of the device by helping the user avoid unintentionally executing an operation using the application and simultaneously allowing the user to recognize that authentication is required before the operation will be performed. Providing additional control of the device in this manner without cluttering the UI with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently 
     In some examples, the biometric authentication interface (e.g.,  1512 ) is displayed ( 1606 ) over a portion of the application interface (e.g.,  1506 ). In some examples, the biometric authentication interface (e.g.,  1512 ) is not displayed over the entirety of the application interface (e.g.,  1506 ) and at least a portion of the application interface (e.g.,  1506 ) remains displayed without being overlaid. In some examples, the biometric authentication interface (e.g.,  1512 ) is at least partially translucent. In some examples, the biometric authentication interface (e.g.,  1512 ) is at least partially translucent (or transparent) such that the application interface (e.g.,  1506 ) is at least partially visible through the biometric authentication interface (e.g.,  1512 ). In some examples, the biometric authentication interface (e.g.,  1512 ) blurs the underlying content, so that the appearance of the biometric authentication interface (e.g.,  1512 ) is based on a portion of blurred content under the biometric authentication interface (e.g.,  1512 ). In some examples, the biometric authentication interface (e.g.,  1512 ) is displayed in response to the loading of the application ( 1608 ). In some examples, the biometric authentication interface (e.g.,  1512 ) is displayed in response to the user loading (e.g., initiating or resuming execution of) an application on the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ). In some examples, the biometric authentication interface (e.g.,  1512 ) is loaded after the application is displayed. In some examples, the biometric authentication interface (e.g.,  1512 ) and application interface (e.g.,  1506 ) are displayed simultaneously. In some examples, the biometric authentication interface (e.g.,  1512 ) is displayed in response to detecting a user interaction with the application interface (e.g.,  1506 ) that corresponds to a request to access content that requires authentication ( 1610 ). In some examples, the request for authentication is a selection of an authentication affordance (e.g.,  1508 ) or the performance of a gesture. In some examples, the application interface (e.g.,  1506 ) includes the authentication affordance ( 1506 ) (e.g., log-in affordance). 
     While displaying the biometric authentication interface (e.g.,  1512 ), prior to obtaining the biometric data corresponding to at least a portion of the biometric feature, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) prepares to use the one or more biometric sensors (e.g.,  1503 ). In some examples, in response to display of the log-in affordance (e.g.,  1508 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) prepares to use (e.g., readies) the one or more biometric sensors. In some examples, preparing to use the one or more biometric sensors (e.g.,  1503 ) includes transitioning the sensors (e.g.,  1503 ) from a low-power state (e.g., an unpowered state or a sleep state) to a low-latency state (e.g., a partial power state or a full power state, a pre-warmed state). In this manner, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) optionally reduces the amount of time required to perform biometric authentication when displaying the biometric authentication interface (e.g.,  1512 ). In some examples, when the one or more biometric sensors (e.g.,  1503 ) are in the low-power state it takes a first amount of time to attempt biometric authentication using the one or more biometric sensors, and when the one or more biometric sensors (e.g.,  1503 ) are in the low-latency state it takes a second amount of time, less than the first amount of time, to attempt biometric authentication using the one or more biometric sensors (e.g.,  1503 ). While displaying the biometric authentication interface (e.g.,  1512 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) obtains ( 1612 ), from the one or more biometric sensors (e.g.,  1503 ), the biometric data corresponding to at least a portion of a biometric feature. In some examples, the biometric feature is a face and the biometric data is data corresponding to a portion of the face. 
     In response to obtaining, from the one or more biometric sensors, biometric data corresponding to at least a portion of a biometric feature, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) determines ( 1614 ), based on the biometric data, whether the at least a portion of the biometric feature satisfies biometric authentication criteria. Determining, based on the obtained biometric data, whether the at least a portion of the biometric feature satisfies biometric authentication criteria enables a quick and efficient authentication process that allows the user to easily provide and proceed with an authentication operation with minimal input. Reducing the number of inputs needed to perform an operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) determines whether a face or a fingerprint of the user matches stored information about face(s) and/or fingerprint(s) that are authorized for use in biometric authentication at the device (e.g.,  100 ,  300 ,  500 ,  1500 ). In some examples, determining, based on the biometric data, whether the at least a portion of the biometric feature satisfies biometric authentication criteria includes displaying ( 1616 ) a biometric authentication analysis animation. In some examples, the biometric authentication animation includes displaying a sequence of interface objects (e.g.,  1514 ,  1515 ,  1516 ,  1517 ,  1518 ,  1519 ) (e.g., glyphs). A first interface object (e.g.,  1514 ) indicates that biometric authentication has been initiated, a second interface object (e.g.,  1517 ) indicates that the device (e.g.,  100 ,  300 ,  500 ,  1500 ) is processing the biometric data, and a third interface object (e.g.,  1518 ,  1519 ) indicates whether the biometric authentication succeeded or failed. In some examples, the first interface object (e.g.,  1514 ) is substantially square in shape and the second interface object (e.g.,  1517 ) is substantially circular in shape. In some examples, displaying a biometric authentication analysis animation includes rotating one or more rings around an interface object (e.g.,  1517 ) (e.g., biometric authentication glyph) of the biometric authentication animation. In some examples, the one or more rings are rotated while the device (e.g.,  100 ,  300 ,  500 ,  1500 ) is processing the biometric data to determine if the biometric data satisfies the biometric authentication criteria. Rotation of the rings optionally simulates rotation of rings around a sphere. In some examples, once the device (e.g.,  100 ,  300 ,  500 ,  1500 ) has finished processing the biometric data, the one or more rings are overlaid with one another to demonstrate that the processing has completed. In some examples, displaying a biometric authentication analysis animation includes changing an appearance of an animated object (e.g.,  1514 ,  1515 ,  1516 ,  1517 ,  1518 ,  1519 ) on a platter (e.g.,  1512 ) that has an appearance based on underlying content (e.g.,  1506 ,  1507 ,  1522 ). In some examples, as the appearance of the animated object changes, the appearance of the platter changes. In some examples, when the animated object gets darker, the platter gets darker, when the animated object gets lighter, the platter gets lighter. In some examples, the appearance of the platter changes as appearance of the animated object (e.g.,  1514 ,  1515 ,  1516 ,  1517 ,  1518 ,  1519 ) changes, even when the underlying content (e.g.,  1506 ,  1507 ,  1522 ) on which appearance of the platter (e.g.,  1512 ) is based does not change. In some examples, one or more colors of the biometric authentication analysis animation are based on one or more colors of the application interface (e.g.,  1506 ). In some examples, the colors of the animation are selected based on one or more colors of the application interface (e.g.,  1506 ,  1507 ,  1522 ) or another interface associated with the application. Colors optionally are derived, for instance, based on colors used for controls and/or icons of the application. In this manner, the animation are, optionally, visually coordinated with the application interface (e.g.,  1506 ,  1507 ,  1522 ), providing a more robust user experience. In some examples, prior to displaying the biometric authentication analysis animation, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) determines one or more colors of the animation based on an analysis of the color scheme of the application interface (e.g.,  1506 ) or data corresponding to the application interface (e.g.,  1506 ). In some examples, further in response to obtaining, from the one or more biometric sensors (e.g.,  1503 ), biometric data corresponding to at least a portion of a biometric feature, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) changes a size of an interface object (e.g.,  1514 ) (e.g., a biometric authentication glyph) of the biometric authentication interface (e.g.,  1512 ) from a first size to a second size and changes the size of the interface object (e.g.,  1514 ) from the second size to the first size. In some examples, once the biometric data has been captured by the one or more biometric sensors (e.g.,  1503 ), the interface object (e.g.,  1514 ) (e.g., biometric authentication glyph) is increased from an initial size and subsequently returned to the initial size to create a “bounce” effect. 
     In accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria ( 1636 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) provides ( 1620 ) authentication information to the application indicating the biometric authentication criteria have been satisfied with respect to the one or more portions of the biometric feature. Providing authentication information to the application in accordance with the determination that the at least a portion of the biometric feature satisfies biometric authentication criteria enhances the security of the device and reduces the number of fraudulent transfers that can occur. Enhancing device security and reducing the number of fraudulent transfers enhances the operability of the device and makes the user-device interface more secure (e.g., by reducing fraud when operating/interacting with the device). 
     In some examples, the authentication information is provided to the application generating the application interface (e.g.,  1506 ) by the operating system. In some examples, further in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria, after providing authentication information to the application, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) maintains ( 1624 ) display of the biometric authentication interface (e.g.,  1512 ) for a predetermined amount of time. In some examples, further in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) displays ( 1622 ) a biometric authentication success animation including a first representation of a simulation of a biometric feature (e.g.,  1518 ) indicating the at least a portion of the biometric feature satisfies the biometric authentication criteria. 
     In some examples, in response to successful biometric authentication, the device (e.g.,  100 ,  300 ,  500 ,  1500 ) displays an animation including a interface object (e.g.,  1518 ) indicating that the biometric authentication was successful. In some examples, further in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature satisfies biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) provides a success tactile output (e.g.,  1520 ) indicating that the at least a portion of the biometric feature satisfies the biometric authentication criteria. Displaying an animation indicating that the biometric authentication was successful provides the user with visual feedback of the operation being performed and enables the user to quickly recognize that the operation was successful. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to achieve an intended result by providing feedback indicative of an input that will cause the device to generate the intended result and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     After maintaining display of the biometric authentication interface (e.g.,  1512 ) for a predetermined amount of time, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) ceases ( 1626 ) to display the biometric authentication interface (e.g.,  1512 ). In some examples, the application receives an indication of authentication prior to the device (e.g.,  100 ,  300 ,  500 ,  1500 ) ceasing to display the biometric authentication interface (e.g.,  1512 ); this allows the application to provide (e.g., display) an interface of the application (e.g.,  1522 ), such as a “main application” interface or post log-in interface, prior to transition from the biometric authentication interface (e.g.,  1512 ). In some examples, the biometric authentication interface (e.g.,  1512 ) ceases to be displayed a predetermined amount of time after authentication. In some examples, the biometric authentication interface (e.g.,  1512 ) ceases to be displayed a predetermined amount of time after the application has performed an operation in accordance with the biometric authentication (e.g., displaying an unlocked user interface (e.g.,  1522 )). 
     In accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria ( 1628 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) displays ( 1630 ) a biometric authentication failure animation including a second representation of a simulation of a biometric feature (e.g.,  1519 ) indicating the at least a portion of the biometric feature does not satisfy biometric authentication criteria. Displaying a biometric authentication failure animation in accordance with a determination that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria provides the user with visual feedback of a failure or an error in the operation being performed and enables the user to quickly recognize that the operation was unsuccessful. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to achieve an intended result by providing feedback indicative of an input that will cause the device to generate the intended result and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in response to unsuccessful biometric authentication, the device (e.g.,  100 ,  300 ,  500 ,  1500 ) displays an animation including an interface object (e.g.,  1519 ) indicating that the biometric authentication was unsuccessful. Displaying an animation including an interface object indicating that the biometric authentication was unsuccessful in response to unsuccessful biometric authentication provides the user with visual feedback of a failure or an error in the operation being performed and enables the user to quickly recognize that the operation was unsuccessful. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to achieve an intended result by providing feedback indicative of an input that will cause the device to generate the intended result and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, during the animation, the interface object (e.g.,  1519 ) moves (e.g., tilts and/or shifts) in a predetermined manner (e.g., side to side) to indicate the failure. In some examples, the device (e.g.,  100 ,  300 ,  500 ,  1500 ) generates a tactile output (e.g.,  1526 ) or a sequence of tactile outputs that correspond to the biometric authentication failure animation (e.g., tactile outputs are generated as the simulation of the biometric feature moves back and forth). Outputting a tactile output or a sequence of tactile outputs that correspond to the biometric authentication failure animation further alerts that user that the authentication was unsuccessful and enables the user to quickly identify that authentication is still needed to proceed with the operation. Providing improved tactile feedback to the user enhances the operability of the device and makes the user-device interface more efficient which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the second representation of the simulation of the biometric feature (e.g.,  1519 ) is a three-dimensional object. Displaying a three-dimensional object as the second representation of the simulation of the biometric provides the user with an easily recognizable visual feedback about a state of the operation (e.g., whether the transfer was successful or unsuccessful) and, because the object is three-dimensional, further enables the user to more easily perceive the object. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device, by enhancing legibility of user interface elements to the user while the device is at natural viewing angles) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the second representation (e.g.,  1519 ) is a three-dimensional face performing a head shake. In some examples, displaying the biometric authentication failure animation includes alternating rotation of the second representation (e.g.,  1519 ) between rotation in a first direction about an axis parallel to the display and rotation in a second direction about the axis parallel to the display (e.g.,  1502 ). In some examples, displaying the biometric authentication failure animation includes emphasizing a boundary of the biometric authentication interface (e.g.,  1512 ) relative to the application interface (e.g.,  1506 ). In some examples, the biometric authentication interface (e.g.,  1512 ), or the boundary thereof, shrinks and/or retracts to create a visual “bounce” effect. In some examples, further in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) provides a failure tactile output (e.g.,  1526 ) different than the success tactile output (e.g.,  1520 ). In some examples, further in accordance with a determination, based on the biometric data, that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) displays ( 1632 ) a failure interface (e.g.,  1540 ). In some examples, the failure interface (e.g.,  1540 ) includes a visual indication that biometric authentication has failed. In some examples, when the biometric authentication fails, the application interface (e.g.,  1506 ) does not change (e.g., the application remains on a log-in (e.g.,  1506 ) or authentication user interface). In some examples, when the biometric authentication fails, the application user interface (e.g.,  1506 ) changes to indicate the failure of the biometric authentication. In some examples, the failure interface (e.g.,  1540 ) includes a retry affordance (e.g.,  1546 ) ( 1634 ). In some examples, the failure interface (e.g.,  1540 ) includes a cancellation affordance (e.g.,  1548 ) ( 1636 ). In some examples, the failure interface (e.g.,  1540 ) includes an alternative authentication affordance (e.g.,  1544 ) ( 1638 ). 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) receives ( 1640 ) an input (e.g.,  1550 ) corresponding to a selection of the retry affordance (e.g.,  1546 ). In response to receiving an input (e.g.,  1550 ) corresponding to a selection of the retry affordance (e.g.,  1546 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) obtains ( 1642 ), from the one or more biometric sensors (e.g.,  1503 ), second biometric data corresponding to at least a portion of a second biometric feature. In some examples, the second biometric feature (e.g. a face) is the same biometric feature as the biometric feature from which the initial biometric data was obtained. In some examples in which the second biometric feature is the same biometric feature, the portion of the second biometric feature is a different portion of the same biometric feature from which the initial biometric data was obtained. In some examples, the portion is the same portion of the same biometric feature. In some examples, the second biometric feature is a different biometric feature than the initial biometric feature. 
     After obtaining the second biometric data that corresponds to at least a portion of the second biometric feature, in accordance with a determination, based on the second biometric data, that the at least a portion of the second biometric feature satisfies second biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) provides ( 1646 ) second authentication information to the application indicating the second biometric authentication criteria have been satisfied with respect to the one or more portions of the second biometric feature. In some examples, the second biometric authentication criteria are the same as the initial biometric authentication criteria. In some examples, the second biometric authentication criteria are different from the initial biometric authentication criteria. In some examples, the second authentication information is the same as the authentication information. In some examples, the second authentication information is different from the authentication information. In some examples, the authentication information is provided to the application generating the application interface (e.g.,  1506 ) by the operating system. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) receives ( 1646 ) an input corresponding to selection of the cancellation affordance. In response to receiving the input corresponding to selection of the cancellation affordance, the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) ceases ( 1648 ) to display the biometric authentication interface (e.g.,  1512 ). In some examples, selection of the cancellation affordance dismisses the failure interface (e.g.,  1540 ), while maintaining the application interface (e.g.,  1506 ). In some examples, selection of the cancellation affordance also causes the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) to provide information to the application indicating that the first and/or second biometric authentication criteria have not been met. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) receives ( 1650 ) an input (e.g.,  1548 ) corresponding to selection of the alternative authentication affordance (e.g.,  1544 ). Providing an alternative authentication affordance (e.g., to provide an alternative method for providing the authentication, in addition to or alternatively to the biometric authentication) allows the user to easily provide authentication for an operation using a different authentication method if the current authentication method is or continues to be unsuccessful. Providing additional control options (e.g., for providing authentication) in this manner without cluttering the UI with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In response to receiving the input (e.g.,  1548 ) corresponding to selection of the alternative authentication affordance (e.g.,  1544 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) displays ( 1652 ) an alternative authentication interface (e.g.,  1562 ). In some examples, the alternative authentication interface (e.g.,  1562 ) is a non-biometric authentication interface (e.g.,  1512 ). In some examples, the alternative authentication interface (e.g.,  1562 ) allows a user to authenticate using a password and/or passcode. In some examples, the application determines which forms of authentication are accepted by the alternative authentication interface (e.g.,  1562 ). In some examples, one or more preferences of the application determine which forms of authentication are accepted by the application. In some examples, the alternative authentication affordance (e.g.,  1562 ) is included in the failure interface (e.g.,  1540 ) in response to more than a predefined number of consecutive failures of biometric authentication (e.g., two failed authentication attempts, three failed authentication attempts, four failed authentication attempts, etc.). In some examples, the alternative authentication interface (e.g.,  1562 ) is an application-level authentication interface ( 1654 ). In some examples, in response to receiving the input corresponding to selection of the alternative authentication affordance (e.g.,  1544 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) ceases ( 1656 ) to display the biometric authentication interface (e.g.,  1512 ). In some examples, selection of the alternative authentication affordance (e.g.,  1544 ) causes the device (e.g.,  100 ,  300 ,  500 ,  1500 ) to cease displaying the alternative authentication affordance (e.g.,  1544 ) and transition to an alternative authentication interface (e.g.,  1562 ) operating at the application level. Accordingly, a user optionally authenticates with the application using credentials associated with the application (e.g., a user optionally logs in using a user name and password for the application). In some examples, the application-level alternative authentication interface (e.g.,  1562 ) optionally includes an affordance to reinitiate biometric authentication. This, in turn, would case the electronic device (e.g.,  100 ,  300 ,  500 ,  1500 ) to redisplay the biometric authentication interface (e.g.,  1512 ) and authenticate at the system or operating system level. 
     Note that details of the processes described above with respect to method  1600  (e.g.,  FIGS. 16A-16E ) are also applicable in an analogous manner to other methods described. For example, method  1600  optionally includes one or more of the characteristics of the various methods described herein with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1800 ,  2000 ,  2200 ,  2500 , and  2700 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication, such as the biometric authentication described with reference to  FIGS. 15E-I . For another example, the biometric authentication interface as described in method  1800  can be used to implement the biometric authentication interface (e.g.,  1512 ). For brevity, these details are not repeated below. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 16A-16E  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, providing operation  1620  and maintaining operation  1624  are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 17A-17AJ  illustrate exemplary user interfaces for biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary example of the user interfaces illustrated in  FIGS. 17A-17AJ  are used to illustrate the processes described below, including the processes in  FIGS. 18A-18D . 
       FIG. 17A  illustrates an electronic device  1700  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary example illustrated in  FIGS. 17A-17AJ , electronic device  1700  is a smartphone. In other examples, electronic device  1700  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  1700  has a display  1702 , one or more input devices (e.g., touchscreen of display  1702 , a button  1704 , a mic), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  1703 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  1703  are the one or more biometric sensors  703 . In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 17A , the electronic device  1700  displays, on display  1702 , a landing page interface of an application including a log-in affordance  1706 . As seen in  FIG. 17A , the application is a browser or mobile application, and the interface corresponds to a website (onlinestore.com). While displaying the landing page interface, the electronic device  1700  detects activation of the log-in affordance  1706 . As shown in  FIG. 17A , the activation is a tap gesture  1708  on log-in affordance  1706 . 
     In  FIG. 17B , in response to detecting tap gesture  1708  on log-in affordance  1706 , the electronic device  1700  displays (e.g., replaces display of the landing page interface with) an application interface of the application including an unsecured data fillable field  1710  (labelled “username”), a secured data fillable field  1712  (labelled “password”), and a submit affordance  1714 . The electronic device further displays a biometric authentication glyph (e.g., icon) in the secured data fillable field  1712 . As will be described in further detail, the biometric authentication glyph indicates that the secured data fillable field  1712  is associated with secured data and/or that biometric authentication is required to autofill the secured data fillable field  1712 . 
     While displaying the application interface, the electronic device  1700  detects a request to autofill the unsecured data fillable field  1710 . For example, as shown in  FIG. 17B , the request to autofill the unsecured data fillable field  1710  is a tap gesture  1718  indicating a selection of the unsecured data fillable field  1710 . 
     In  FIG. 17C , in response to detecting the request to autofill the unsecured data fillable field  1710 , the electronic device  1700  displays (e.g., overlays on the application interface) an input interface  1720  including a keyboard, such as a software keyboard, and/or keypad and an autofill affordance  1722 . While displaying the input interface  1720 , the electronic device  1700  detects activation of the autofill affordance  1722 . For example, as shown in  FIG. 17A , the activation is a tap gesture  1724  on autofill affordance  1722 . 
     In  FIG. 17D , in response to detecting tap gesture  1724 , the electronic device displays (e.g., replacing the autofill affordance  1722  and/or one or more other affordances of the input interface  1720 ) a plurality of candidate input affordances  1725  for autofilling the unsecured data fillable field  1710 . In the illustrated example, the fillable field  1710  is associated with a user name. Accordingly, in some examples, each of the candidate inputs affordances  1725  serves as a reference to a respective candidate user name. 
     While displaying the candidate input affordances  1725  of the input interface  1720 , the electronic device detects activation of a candidate input affordance  1725 . For example, as shown in  FIG. 17D , the activation is a tap gesture  1726  on a candidate input affordance  1725 . In  FIG. 17E , in response to detecting tap gesture  1726 , the electronic device  1700  autofills the unsecured data fillable field with a candidate input  1728  corresponding to the activated candidate input affordance  1725 . 
     As described, in response to detecting tap gesture  1724 , the electronic device provides (e.g., displays) candidate input affordances corresponding to respective candidate inputs. In some examples, in response to detecting tap gesture  1724 , the electronic device determines whether multiple candidate inputs are available. If so, the electronic device  1700  provides the candidate input affordances as described. Any number of candidate input affordances optionally are provided in this manner. If not (e.g., only a single candidate input is available), the electronic device, optionally, autofills the unsecured data fillable field  1710  without providing the candidate inputs. 
     With reference to  FIG. 17F , while displaying the application interface, the electronic device  1700  detects a request to autofill the secured data fillable field  1712 . For example, the request to autofill the secured data fillable field  1712  is a tap gesture  1730  indicating a selection of the secured data fillable field  1712 . 
     In  FIG. 17G , in response to detecting the request to autofill the secured data fillable field  1712 , the electronic device  1700  initiates biometric authentication. In some examples, initiating biometric authentication includes obtaining (e.g., capturing with the one or more biometric sensors) data corresponding to a biometric feature of a user. In some examples, initiating biometric authentication further includes displaying a biometric authentication interface  1732  having a biometric authentication glyph  1734 . The biometric authentication glyph  1734  is a simulation of a representation of the biometric feature in some examples. The biometric authentication interface  1732  is overlaid on at least a portion of the application interface in some examples. 
     With reference to  FIG. 17H , in response to obtaining data, the electronic device processes the biometric data, for instance to determine, based on the biometric data, whether the biometric feature satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template). While the electronic device processes the biometric data, the electronic device, optionally, displays (e.g., replaces display of the biometric authentication glyph  1734  with) a biometric authentication glyph  1738  in the biometric authentication interface  1732  indicating that the biometric data is being processed. 
     In  FIG. 17I , the electronic device  1700  determines that the biometric feature satisfies the biometric authentication criteria. In response, the electronic device displays (e.g., replaces display of the biometric authentication glyph  1738  with) a biometric authentication glyph  1740  in the biometric authentication interface  1732  indicating that the biometric authentication was successful. Additionally or alternatively, the electronic device outputs a tactile output  1742  indicating the biometric authentication was successful. After indicating the biometric authentication is successful, the electronic device, as shown in  FIG. 17J , autofills the secured data fillable field with an appropriate password  1743 . In some examples, the electronic device further autofills a second fillable field, such as the unsecured fillable field  1710  (e.g., with user name  1728 ), in response to the successful biometric authentication. It will be appreciated that any number and/or type of fillable fields optionally are autofilled in response to successful biometric authentication. 
     While displaying the application interface with the autofilled fillable fields  1710 ,  1720 , the electronic device detects activation of a submission affordance  1714 . By way of example, as shown in  FIG. 17J , the activation is a tap gesture  1744  on the submission affordance  1714 . In response, the user optionally is authenticated with the application and the electronic device optionally shows a home interface, such as the home interface  1782  of  FIG. 17S , referenced further below. 
     Alternatively, in  FIG. 17K , the electronic device  1700  determines that the biometric feature does not satisfy the biometric authentication criteria. In response, the electronic device displays (e.g., replaces display of the biometric authentication glyph  1738  with) a biometric authentication glyph  1746  in the biometric authentication interface  1732  indicating that the biometric authentication was unsuccessful (e.g., failed). Optionally, the electronic device outputs a tactile output  1750  indicating the biometric authentication was unsuccessful. In some examples, the tactile output  1750  is the same as the tactile output  1742 . In some examples, the tactile output  1750  is different than the tactile output  1742 . After having indicated that the biometric authentication was unsuccessful, the electronic device ceases display of the biometric authentication interface, as illustrated in  FIG. 17L . 
     In some examples, the biometric authentication interface  1732  includes an animation and/or one or more of the biometric authentication glyphs of the biometric authentication interface  1732  are animated. By way of example, the biometric authentication glyph  1738  includes rings having a spherical rotation and/or the biometric authentication glyph  1746  moves side to side to simulate a “shake” movement. 
     With reference to  FIG. 17M , in some examples, further in response to unsuccessful biometric authentication, the electronic device  1700  displays a failure interface, such as the failure interface  1752 . The failure interface includes a biometric authentication glyph  1754 , an alternative authentication affordance  1756 , a retry affordance  1758 , and a cancel affordance  1760 . In some examples, activation of the retry affordance  1758  causes the electronic device to reinitiate biometric authentication, as described above. In some examples, the electronic device performs the biometric authentication only if a threshold number of failed biometric authentication attempts have not been made. In some examples, activation of the cancel affordance causes the electronic device  1700  to cease display of the failure interface  1752 . 
     With reference to  FIG. 17N , in response to an activation of the alternative authentication affordance  1756 , such as the tap gesture  1762 , the electronic device  1700  displays (e.g., replaces display of the failure interface  1752  with) an alternative authentication interface  1766  ( FIG. 17O ), with which the user authenticates using an alternative form of authentication than that associated with the biometric feature (e.g., fingerprint authentication, password authentication, passcode authentication, pattern authentication where pattern authentication includes selection of a plurality of items in a predefined pattern or movement of a contact or other input in a predefined pattern). As shown in  FIG. 17O , the user optionally touches a fingerprint sensor  1764  of the electronic device with a finger to authenticate. 
       FIG. 17P  illustrates another exemplary failure interface  1766  including an alternative authentication affordance  1770 . With reference to  FIG. 17Q , while displaying the failure interface  1766 , the electronic device  1766  detects activation of the alternative authentication affordance  1770 . By way of example, the activation is a tap gesture  1776  on log-in affordance  1770 . In response to detecting tap gesture  1776 , the electronic device  1700  displays an alternative authentication interface  1778 . In some examples, the alternative authentication interface  1778  is a password (or passcode) interface by which a user can provide a password (or passcode) to authenticate. 
     In  FIG. 17R , in response to authentication (e.g., alternative authentication), the secured data fillable field is autofilled with the password  1743 , and optionally, the unsecured data fillable field is autofilled with user name  1728 . In this manner, a user can, optionally, leverage autofill functionality despite unsuccessful biometric authentication. While displaying the application interface with autofilled fillable fields  1710 ,  1720 , the electronic device detects activation of a submission affordance  1714 . By way of example, the activation is a tap gesture  1780  on the submission affordance  1714 . In response, the user optionally is authenticated with the application and the electronic device optionally shows a home interface, such as the home interface  1782  of  FIG. 17S . 
     In  FIG. 17T , the electronic device  1700  displays, on display  1702 , an application interface  1784  including a secured data fillable field  1786 . In response to a request to autofill the secured data fillable field  1786  (e.g., selection of the secured data fillable field  1786 ), the electronic device  1700  displays an input interface  1788  including an autofill affordance  1790 , as illustrated. 
     While displaying the autofill affordance  1790  of the input interface  1788 , the electronic device  1700  detects activation of the autofill affordance  1790 . For example, as shown in  FIG. 17U , the activation is a tap gesture  1792  on the autofill affordance  1792 . 
     With reference to  FIGS. 17V-X , in response to detecting tap gesture  1792 , the electronic device  1700  initiates biometric authentication to determine whether at least a portion of the biometric feature, as determined based on biometric data corresponding to the biometric feature, satisfies the biometric authentication criteria, described at least with reference to  FIGS. 17G-I . 
     In  FIG. 17Z , in response to successful biometric authentication, the electronic device  1700  displays (e.g., replaces display of the biometric authentication interface  1732  with) a candidate selection interface  1794  including a plurality of candidate input affordances  1792  for autofilling the secured data fillable field  1786 . In some examples, the candidate selection interface  1794  is displayed without a keyboard. In the illustrated example, the fillable field  1786  is associated with credit cards (e.g., fillable field  1786  is flagged as associated with financial transactions). Accordingly, in some examples, each of the candidate inputs affordances  1792  serves as a reference to a respective credit card (e.g., credit card number and/or one or more other respective candidate values associated with the credit card). 
     While displaying the candidate input affordances  1792 , the electronic device  1700  detects activation of a candidate input affordance  1792 . For example, as shown in  FIG. 17Z , the activation is a tap gesture  1795  on a candidate input affordance  1792 . In  FIG. 17Z , in response to detecting tap gesture  1795 , the electronic device  1700  autofills the secured data fillable field with the candidate input  1796  corresponding to the activated candidate input affordance  1792 . 
     While displaying the application interface  1784  with autofilled fillable field  1786 , the electronic device detects activation of a submission affordance  1798 . By way of example, the activation is a tap gesture  1702 A on the submission affordance  1798 . In response, the autofilled credit card optionally is submitted using the application, for instance, for authentication or payment purposes. 
     While description is made herein with respect to performing biometric authentication prior to providing candidate input affordances when autofilling secured data fillable fields, it will be appreciated that, in some examples, candidate input affordances are provided prior to biometric authentication. With reference to  FIG. 17AA , for instance, in response to a request to autofill the secured data fillable field  1786 , the electronic device  1700  displays an input interface including a plurality of candidate input affordances  1704 A. Each of the candidate inputs  1704 A is a reference to (e.g., representation of) a candidate input value in some examples. 
     As illustrated in  FIG. 17AB , while displaying the input interface including a plurality of candidate input affordances  1704 A, the electronic device detects activation of a candidate input affordance  1704 A. By way of example, the activation is a tap gesture  1706 A on a candidate input affordance  1704 A. With reference to  FIGS. 17AC -AE, in response, the electronic device performs biometric authentication, as described. In  FIG. 17AF , the electronic device  1700  has determined that the biometric authentication is successful, and autofills the secured data Tillable field  1786  with the selected candidate input corresponding to the selected candidate input affordance  1704 A. 
     In  FIG. 17AG , the electronic device instead determines that the biometric authentication was unsuccessful. In response, the electronic device  1700  ceases display of the biometric authentication interface, as illustrated in  FIG. 17AH . 
     As mentioned above, the exemplary example of the user interfaces illustrated in  FIGS. 17A-17AH  described above relate to the exemplary example of the user interfaces illustrated in  FIGS. 18A-18AH  described below. Therefore, it is to be understood that the processes described above with respect to the exemplary user interfaces illustrated in  FIGS. 17A-17AF  and the processes described below with respect to the exemplary user interfaces illustrated in  FIGS. 18A-18AH  are largely analogous processes that similarly involve initiating and managing transfers using an electronic device (e.g.,  100 ,  300 ,  500 ,  700 ) 
       FIGS. 18A-18D  are a flow diagram illustrating a method for performing biometric authentication using an electronic device in accordance with some examples. Method  1800  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1700 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric feature by the one or more biometric sensors. Some operations in method  1800  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  1800  provides an intuitive way for performing authentication of biometric features. The method reduces the cognitive burden on a user for performing authentication of biometric features, thereby creating a more efficient human-machine interface and intuitive user experience. For battery-operated computing devices, enabling a user to manage authentication of biometric features faster and more efficiently conserves power and increases the time between battery charges. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) detects ( 1802 ) a selection of the fillable field (e.g.,  1710 ,  1712 ,  1786 ). In some examples, in response to detecting the selection of the fillable field (e.g.,  1710 ,  1712 ,  1786 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays ( 1804 ) an input interface (e.g.,  1720 ,  1788 ) including a plurality of user interface objects (e.g.,  1725 ,  1793 ,  1704 A) that correspond to candidate inputs for the fillable field (e.g.,  1710 ,  1712 ,  1786 ). 
     In some examples, prior to receiving the request (e.g.,  1718 ,  1724 ,  1726 ,  1730 ,  1792 ,  1795 ,  1706 A) to autofill the at one fillable field (e.g.,  1710 ,  1712 ,  1786 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) receives a selection (e.g.,  1718 ,  1730 ) of the fillable field (e.g.,  1710 ,  1712 ,  1786 ). In some examples, the selection (e.g.,  1718 ,  1730 ) of the fillable field (e.g.,  1710 ,  1712 ,  1786 ) is a user selection of the fillable field (e.g.,  1710 ,  1712 ,  1786 ) displayed in the application interface using an input device, such as a mouse or a button. In some examples, in response to the selection of the fillable field (e.g.,  1710 ,  1712 ,  1786 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays ( 1806 ) the autofill affordance (e.g.,  1722 ,  1790 ). In some examples, the autofill affordance (e.g.,  1722 ,  1790 ) is displayed in combination with a keyboard (or keypad)). 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays ( 1808 ), on the display, an application interface including a fillable field (e.g.,  1710 ,  1712 ,  1786 ). Displaying an application interface including a fillable field provides the user with visual feedback indicating that an input can be made to a particular region of the application interface. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, displaying, on the display (e.g.,  1702 ), an application interface including a fillable field (e.g.,  1710 ,  1712 ,  1786 ) includes, in accordance with the fillable field (e.g.,  1712 ,  1786 ) being associated with data of the second type, displaying ( 1810 ) the fillable field (e.g.,  1712 ,  1786 ) with a first visual treatment. Displaying the fillable field with a particular visual treatment (e.g., the first visual treatment) in accordance with the fillable field being associated with data of a particular type (e.g., the second type) provides visual feedback that allows the user quickly and easily recognize that the fillable field is associated with a particular data type. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, data of the second type includes data for which authentication is required in order to be autofilled, such as payment information, a password, and/or a username. In some examples, the first visual treatment is a visual effect, such as a specific color scheme, highlighting, or animation. In some examples, the first visual treatment includes a first color scheme, such as a pattern of one or more colors. In some examples, the first visual treatment includes a biometric authentication interface object (e.g.,  1716 ) associated with (e.g., within or adjacent to) the fillable field (e.g.,  1712 ,  1786 ). 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays a biometric authentication glyph (e.g.,  1716 ) or icon in or near fields (e.g.,  1712 ,  1786 ) that are associated with biometric authentication that is not displayed in or near fields (e.g.,  1710 ) that are not associated with biometric authentication. Displaying the biometric authentication glyph or icon in or near fields that are associated with biometric authentication and not displaying the biometric glyph or icon in or near fields that are not associated with biometric authentication provides easily recognizable visual feedback about the which fields relate to or require biometric authentication and which fields do not relate to or require biometric authentication. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, displaying on the display, an application interface including a fillable field includes, in accordance with the fillable field (e.g.,  1710 ) being associated with data of the first type, displaying ( 1812 ) the fillable field (e.g.,  1710 ) with a second visual treatment, different than the first visual treatment. In some examples, data of the first type includes data for which authentication is not required in order to be autofilled, such as contact information including a name, address, phone number, zip code, etc. In some examples, the second visual treatment is the absence of the first visual treatment. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) highlights the fillable field (e.g.,  1712 ,  1786 ) with a different color, a biometric authentication glyph (e.g.,  1716 ), and/or text indicating the fillable field (e.g.,  1712 ,  1786 ) are, optionally, autofilled responsive to successful biometric authentication. In some examples, the second visual treatment includes a second color scheme, different than the first color scheme. Accordingly, in some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays fields (e.g.,  1712 ,  1786 ) that are associated with biometric authentication using a different color from fields (e.g.,  1710 ) that are not associated with biometric authentication. 
     In some examples, displaying, on the display, an application interface including a fillable field (e.g.,  1710 ,  1712 ,  1786 ) includes displaying ( 1814 ) a webpage including the fillable field (e.g.,  1710 ,  1712 ,  1786 ). In some examples, the application interface further includes a submission affordance (e.g.,  1714 ,  1798 ) associated with the fillable field (e.g.,  1710 ,  1712 ,  1786 )). 
     In some examples, while displaying the application interface, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) receives ( 1816 ) a request (e.g.,  1718 ,  1724 ,  1726 ,  1730 ,  1792 ,  1795 ,  1706 A) to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface. In some examples the request is a selection (e.g.,  1724 ,  1792 ) of an autofill affordance (e.g.,  1722 ,  1790 ), a selection (e.g.,  1718 ,  1730 ) of a field, a selection (e.g.,  1726 ,  1795 ,  1706 A) of a candidate text entry, loading a webpage, or any combination thereof. In some examples, receiving the request to autofill the at least one fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface includes receiving ( 1818 ) a selection of an autofill affordance (e.g.,  1722 ,  1790 ) that is displayed on the display (e.g.,  1702 ) of the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ). In some examples, in response to selection (e.g.,  1710 ,  1712 ,  1786 ) of the field (e.g.,  1710 ,  1712 ,  1786 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays a keyboard (or keypad) including an affordance (e.g.,  1722 ,  1790 ) to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ). In response to selection of the affordance, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) initiates biometric authentication. In some examples, receiving the request to autofill the at least one fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface includes receiving ( 1820 ) a selection (e.g.,  1718 ,  1730 ) of the fillable field (e.g.,  1710 ,  1712 ,  1786 ). 
     In some examples, in response to selection of the fillable field (e.g.,  1710 ,  1712 ,  1786 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) initiates biometric authentication without displaying an input interface (e.g.,  1720 , 1788 ). Initiating biometric authentication without displaying an input interface in response to selection of the fillable field enables the user to quickly and efficiently initiate biometric authentication with minimal input. Reducing the number of inputs needed to perform an operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the input interface (e.g.,  1720 ,  1788 ) is displayed in response to selection of fields of a first type (e.g.,  1786 ) (e.g., credit card field) and is not displayed in response to selection of fields of a second type (e.g.,  1712 ) (e.g., password field). In some examples, receiving the request to autofill the at least one fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface includes receiving ( 1822 ) a selection (e.g.,  1726 ,  1795 ,  1706 A) of a reference (e.g.,  1725 ,  1793 ,  1704 A) corresponding to a candidate input associated with data of the second type. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) provides one or more references (e.g.,  1725 ,  1793 ,  1704 A) corresponding to one or more candidate inputs that can be used (e.g., upon selection) to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ). In some examples, a reference is, for instance, a reference to a credit card (e.g., “CC1”) or a reference to a password (“Facebook password”). In some examples, a reference is the candidate itself (e.g., an email address such as “test@test.com”)). In some examples, the selection (e.g.,  1726 ,  1795 ,  1706 A) of the reference (e.g.,  1725 ,  1793 ,  1704 A) to the candidate input is a selection of an affordance of a software keyboard. In some examples, the keyboard is a keypad. In some examples, receiving the request to autofill the at least one fillable field of the application interface includes a selection ( 1824 ) of the fillable field of the webpage. In some examples, receiving the request to autofill the fillable field of the application interface includes receiving ( 1826 ) a selection (e.g.,  1726 ,  1795 ,  1706 A) of a user interface object (e.g.,  1725 ,  1793 ,  1704 A) that corresponds to a respective candidate input of the plurality of candidate inputs. In some examples, in response to selection of the fillable field, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) provides candidate inputs (e.g.,  1725 ,  1793 ,  1704 A) for selection by the user. Thereafter, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) proceeds with biometric authentication. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) identifies all fillable fields (e.g.,  1710 ,  1712 ,  1786 ) when the application interface is loaded and/or determines candidate inputs for one or more of the fields (e.g.,  1710 ,  1712 ,  1786 ). In some examples, autofilling in this manner reduces the number of inputs required to autofill a fillable field (e.g.,  1710 ,  1712 ,  1786 ). In some examples, the request to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ) is based on detection of loading a webpage that includes the fillable field (e.g.,  1710 ,  1712 ,  1786 ). 
     In some examples, in response to receiving the request to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface ( 1828 ), in accordance with a determination that the fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface is associated with data of a first type, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) autofills ( 1830 ) the fillable field (e.g.,  1710 ,  1712 ,  1786 ) with data of the first type. Autofilling the fillable field with data of a particular type (e.g., data of the first type) in accordance with a determination that the fillable field of the application interface is associated with the data of the particular type (e.g., data of the first type) allows the user to bypass having to manually input the data in the fillable field of the application interface. Reducing the number of inputs needed to perform an operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, data of the first type includes data that is unsecured or not secured (e.g., not biometrically secured). In some examples, the unsecured data is a user&#39;s given name, nickname, publically-available phone number, or preference associated with the specific field (e.g., a shoe size for a shoe size field). In some examples, autofilling the fillable field (e.g.,  1710 ,  1712 ,  1786 ) includes populating the field, in response to the request (e.g.,  1718 ,  1724 ,  1726 ,  1730 ,  1792 ,  1795 ,  1706 A), with data stored by the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) or accessible to the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) without requiring further authentication (e.g., further biometric authentication). 
     In some examples, further in response to the request to autofill fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface, in accordance with a determination that the fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application is associated with data of a second type ( 1832 ), while obtaining (e.g., during at least a portion of the obtaining process), from the one or more biometric sensors (e.g.,  1703 ), data corresponding to the biometric feature, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays ( 1834 ) a biometric authentication interface (e.g.,  1732 ). Displaying the biometric authentication interface in accordance with the determination that the fillable field of the application is associated with data of a particular type (e.g., data of the second type) enhances device security by requiring a security verification measure if the data is of a particular type (e.g., of the second type). Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, data of the second type is secured data (e.g., biometrically secured data). In some examples, secured data includes pass word information, credit card information, non-public user information such as an unlisted telephone number, or medical information. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays a biometric authentication interface (e.g.,  1732 ) while performing biometric authentication. In some examples, the biometric authentication interface is displayed over at least a portion of the application interface. In some examples, displaying the biometric authentication interface includes displaying a biometric authentication animation. In some examples, the biometric authentication animation includes an initial animation (e.g., display of first biometric authentication glyph (e.g.,  1734 )), a processing animation (e.g., rotating rings indicating that biometric data is being processed), and either a success animation or a failure animation. In some examples, the failure animation is the same as the initial animation. This feature is described in greater detail above with reference to  FIGS. 15A-15T ). In some examples, the biometric authentication interface includes a representation of a simulation of the biometric feature (e.g.,  1734 ,  1738 ,  1740 ,  1746 ) ( 1836 ). In some examples, the biometric authentication interface includes a representation of a simulation of the biometric feature (e.g.,  1734 ,  1738 ,  1740 ,  1746 ) indicative of the state of the biometric authentication sequence. In some examples, the biometric feature is a face and the representation (e.g.,  1734 ,  1738 ,  1740 ,  1746 ) is a simulation of a face. 
     In some examples, further in response to the request to autofill the fillable field and in accordance with a determination that the fillable field of the application is associated with data of a second type, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) determines whether multiple candidate inputs (e.g., associated with data of the second type) are stored on the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ). Further, in some examples, in accordance with a determination that multiple candidate inputs associated with data of the second type (e.g.,  1793 ,  1704 A) are stored on the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays the multiple candidates. Further, in some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) receives a selection of a candidate input of the displayed multiple candidate inputs. Further, in some examples, in response to receiving the selection (e.g.,  1704 A) of the candidate input, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) obtains, from the one or more biometric sensors (e.g.,  1703 ), the data corresponding to at least a portion of a biometric feature. In some examples, autofilling the fillable field (e.g.,  1712 ,  1786 ) with data of the second type includes autofilling the fillable field (e.g.,  1712 ,  1786 ) with the selected candidate input (e.g.,  1704 A). In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) determines whether multiple candidate inputs are stored on the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) prior to performing biometric authentication. In some examples, once a user has selected a candidate input (e.g.,  1704 A), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) performs the biometric authentication. 
     In some examples, further in response to the request to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ) and in accordance with a determination that the at least a portion of a biometric feature, determined based on the data obtained from the one or more biometric sensors that corresponds to the biometric feature, satisfies biometric authentication criteria ( 1838 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) autofills ( 1840 ) the fillable field (e.g.,  1710 ,  1712 ,  1786 ) with data of the second type. Autofilling the fillable field with data of a particular type (e.g., of the second type) in accordance with the determination that the at least a portion of the biometric feature satisfies the biometric authentication criteria allows the user to bypass having to manually input the data in the fillable field. Reducing the number of inputs needed to perform an operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, if biometric authentication is successful, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) autofills the fillable field (e.g.,  1712 ,  1786 ) with the information in response to the request. Autofilling the fillable field allows the user to bypass having to manually input the data in the fillable field. Reducing the number of inputs needed to perform an operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, in response to receiving the request (e.g.,  1718 ,  1724 ,  1726 ,  1730 ,  1795 ,  1706 A) to autofill the fillable field (e.g.,  1712 ,  1786 ) of the application interface the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) obtains, from the one or more biometric sensors, data corresponding to at least a portion of a biometric feature. In some examples, the data obtained from the one or more biometric sensors is obtained prior to receiving the request to autofill the fillable field of the application interface. In some examples, the data obtained from the one or more biometric sensors is obtained in response to receiving the request to autofill the fillable field (e.g.,  1712 ,  1786 ) of the application interface. In some examples, the data obtained from the one or more biometric sensors (e.g.,  1703 ) is obtained in accordance with a determination that the fillable field (e.g.,  1712 ,  1786 ) of the application is associated with data of a second type. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) autofills the fillable field (e.g.,  1712 ,  1786 ) without displaying, in response to the request to autofill the fillable field, an input interface (e.g.,  1720 ) (e.g., keyboard or keypad). In some examples, the one or more biometric sensors (e.g.,  1703 ) includes a camera (e.g., an IR camera or thermographic camera). In some examples, the data obtained from the one or more biometric sensors (e.g.,  1703 ) that corresponds to the biometric feature includes biometric data obtained using the camera. In some examples, the biometric feature is a face. In some examples, the data obtained from the one or more biometric sensors (e.g.,  1703 ) that corresponds to the biometric feature includes biometric data associated with a portion of the face, and the biometric authentication criteria includes a requirement that the biometric data associated with the face match biometric data associated with an authorized face in order for the biometric authentication criteria to be met. 
     In some examples, in accordance with a determination that the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) has access to a single candidate value of the second type for filling in the fillable field (e.g.,  1712 ,  1786 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) autofills the fillable field (e.g.,  1712 ,  1786 ) with the data of the second type. In some examples, in accordance with a determination that the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) has access to multiple candidate values of the second type for autofilling in the fillable field (e.g.,  1712 ,  1786 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays representations of a plurality of the multiple candidate values. In some examples, candidate values are directly stored on the device and/or otherwise accessible to the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) from another electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) connected to the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ). In some examples, while displaying the representations (e.g.,  1725 ,  1793 ,  1704 A) of the plurality of the multiple candidate values, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) receives a selection (e.g.,  1726 ,  1795 ,  1706 A) of a representation (e.g.,  1725 ,  1793 ,  1704 A) of a respective candidate value of the multiple candidate values and, in some examples, autofills the fillable field (e.g.,  1712 ,  1786 ) with the respective candidate value. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) determines whether the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) has access to multiple instances of data of the second type. In some examples, in response to successful biometric authentication, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) determines whether multiple candidate inputs, for instance, of biometrically secured data (e.g., candidate credit cards), are stored on the device. If so, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) presents (e.g., displays) each of the candidates (e.g.,  1725 ,  1793 ,  1704 A) to the user. In response to a user selection (e.g.,  1726 ,  1795 ,  1706 A) of one of the candidates (e.g.,  1725 ,  1793 ,  1704 A), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) autofills the field (e.g.,  1712 ,  1786 ) using the selected candidate. 
     In some examples, in accordance with the determination, based on the data obtained from the one or more biometric sensors, that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) forgoes ( 1842 ) autofilling the fillable field (e.g.,  1712 ,  1786 ) with data of the second type. Forgoing to autofill the field using the selected candidate in accordance with the determination that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria provides visual feedback by allowing to user to recognize that the authentication was unsuccessful and further provides enhanced device security by forgoing autofilling the fillable field without successful authentication. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device, by enhancing legibility of user interface elements to the user while the device is at natural viewing angles) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. Furthermore, improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, in accordance with the determination, based on the data obtained from the one or more biometric sensors, that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays ( 1844 ) an indication that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria. Displaying the indication that the at least a portion of the biometric feature did not satisfy the biometric authentication criteria provides visual feedback by allowing to user to quickly recognize that the authentication was unsuccessful. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device, by enhancing legibility of user interface elements to the user while the device is at natural viewing angles) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, in response to a failed biometric authentication, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) provides an indication of the failure. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays a message indicating “Biometric Feature Not Recognized” or indicating “Biometric Authentication Inactive,” if a threshold number of biometric attempts has been reached. In some examples, after failure, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) removes any biometric authentication interface displayed over the application interface and/or displays a biometric authentication retry affordance (e.g.,  1758 ) (e.g., in the fillable field (e.g.,  1712 )), selection of which retries biometric authentication. In some examples, in response to determining that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria, the device displays a keypad or keyboard for entering data (e.g., a user name, password, passcode, contact information, credit card information, etc.) into the fillable field (e.g.,  1712 ,  1786 ). 
     In some examples, in accordance with the determination, based on the data obtained from the one or more biometric sensors, that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) ceases to display the biometric authentication interface. In some examples, after failed biometric authentication, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) ceases to display the biometric authentication. As a result, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) resumes display of the application interface, such as a log-in interface (e.g.,  1714 ) of the application. 
     In some examples, in accordance with the determination, based on the data obtained from the one or more biometric sensors, that the at least a portion of the biometric feature does not satisfy the biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays an input interface (e.g.,  1720 ). In some examples, the input interface (e.g.,  1720 ) includes a keypad or keyboard that includes character entry keys for entering a password or passcode. 
     In some examples, in accordance with a determination that biometric authentication is not available, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) prompts the user for an alternative form of authentication. Prompting the user for the alternative form of authentication in accordance with the determination that biometric authentication is not available allows the user to easily provide authentication for an operation using a different authentication method. Providing additional control options (e.g., for providing authentication) in this manner without cluttering the UI with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, biometric authentication fails because a threshold number of failed biometric authentication attempts has been reached since the last successful authentication with the device, or because the biometric sensor cannot be used due to heat, cold, lighting (e.g., there is not enough light or too much light for the device to detect the characteristics of the biometric feature), or other environmental conditions. In some examples, after prompting the user for an alternative form of authentication (e.g., a passcode, password or different form of biometric authentication such as a fingerprint), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) receives an alternative form of authentication. In some examples, further after prompting the user for an alternative form of authentication, in response to receiving the alternative form of authentication, in accordance with a determination that the alternative form of authentication is consistent with authorized authentication information (e.g., a previously stored fingerprint, password, or passcode), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) autofills the fillable field (e.g.,  1712 ,  1786 ). In some examples, further after prompting the user for an alternative form of authentication and further in response to receiving the alternative form of authentication, in accordance with a determination that the alternative form of authentication is not consistent with authorized authentication information, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) forgoes autofilling the fillable field (e.g.,  1712 ,  1786 ). 
     In some examples, after responding to the request to autofill the fillable field of the application interface, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) receives a subsequent request to load the webpage. In some examples, further after responding to the request to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface, in response to the subsequent request to load the webpage, in accordance with a determination that the subsequent request to load the webpage meets authentication retry criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) attempts biometric authentication to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ) in the application interface. In some examples, further after responding to the request to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ) of the application interface and further in response to the subsequent request to load the webpage, in accordance with a determination that the subsequent request to load the webpage does not meet the authentication retry criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) forgoes attempting biometric authentication to autofill the fillable field (e.g.,  1710 ,  1712 ,  1786 ) in the application interface. In some examples, loading a webpage conditionally triggers the autofilling based on predetermined criteria. For example, loading a webpage is treated as a request to autofill the fillable fields in the webpage the first time that a webpage is loaded, but not the second time that the webpage is loaded when the webpage is loaded for the second time within a predetermined amount of time (e.g., within 5 minutes, 1 hour, or 1 day). In some examples, the authentication retry criteria include at least one of a requirement that the webpage has not been loaded within a predetermined amount of time or a requirement that the webpage has not been loaded during the same session. In some examples, the requirement is that the loading is a first instance of loading within a predetermined time and/or that the loading is a first instance of loading within a session. 
     In some examples, after autofilling the fillable field (e.g.,  1710 ,  1712 ,  1786 ) with the data of the first type or the data of the second type, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) receives a selection of the submission affordance (e.g.,  1714 ,  1798 ). In some examples, in response to receiving the selection of the submission affordance, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) ceases to display the application interface. In some examples, further in response to receiving the selection of the submission affordance, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ) displays a second interface (e.g.,  1782 ) generated by the application. In some examples, displaying the second interface includes replacing a log in user Interface of the application with a user interface of the application (e.g.,  1782 ) that includes protected information. 
     Note that details of the processes described above with respect to method  1200  (e.g.,  FIGS. 18A-18D  are also applicable in an analogous manner to the methods described herein. For example, method  1800  optionally includes one or more of the characteristics of the various methods described herein with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  2000 ,  2200 ,  2500 , and  2700 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to  FIGS. 17G-K . For another example, one or more interstitial interfaces as described in methods  2000  and  2700  optionally are displayed in response to receipt of an input prior to completion of a biometric authentication process. For brevity, these details are not repeated herein. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 18A-18D  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, displaying operation  1808 , receiving operation  1816 , and autofilling operation  1830 , are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 19A-19AB  illustrate exemplary user interfaces for biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary example of the user interfaces illustrated in  FIGS. 19A-19AB  are used to illustrate the processes described below, including the processes in  FIGS. 20A-20F . 
       FIG. 19A  illustrates an electronic device  1900  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary example illustrated in  FIGS. 19A-19AB , electronic device  1900  is a smartphone. In other examples, electronic device  1900  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  1900  has a display  1902 , one or more input devices (e.g., touchscreen of display  1902 , a button  1904 , a mic (not displayed)), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  1903 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  1903  are the one or more biometric sensors  703 . In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 19A , the electronic device wakes from a low power (e.g., display-off) state. As illustrated, in some examples, the electronic device  1900  wakes in response to a lift gesture  1906  performed by a user. With reference to  FIGS. 19B-D , in response to the lift gesture  1906 , the electronic device  1900  transitions from the low power state to a moderate power state (e.g., display-dimmed). For example, in  FIG. 19B , the display  1902  of the electronic device  1900  is disabled, and in response to the lift gesture  1906 , the electronic device  1900  gradually increases brightness of the display  1902  over a predetermined period of time as shown in  FIGS. 19C-D . In some examples, the brightness of the display  1902  is increased according to a function, such as a linear function. In some examples, when biometric authentication (e.g., facial recognition authentication) is enabled, the device immediately locks when a hardware button (e.g., the Sleep/Wake button) is pressed and, in some examples, the device locks every time it transitions to sleep mode. 
     With reference to  FIGS. 19C-D , in some examples, while transitioning to and/or operating in a moderate power state (e.g., a state in which the display is on, but not at full operational brightness), the electronic device displays a locked interface  1910 . The locked interface includes for instance, a locked state indicator  1912 , and optionally, one or more notifications  1914 . As shown, the notification  1914  is a message notification associated with a messaging application indicating that the electronic device has received a new message from a contact stored on the electronic device (“John Appleseed”). In some examples, the moderate power state is a locked state. Accordingly, while operating in the moderate power state, the electronic device  1900  operates in a secured manner. By way of example, while operating in the moderate power state, the electronic device does not display contents of the message associated with the notification  1914 . In some examples, the locked state further corresponds to restrictions on access to other data (including other applications) and/or limitations on permissible inputs. 
     In some examples, the electronic device  1900  further displays a flashlight affordance  1907  and a camera affordance  1908 . In some examples, activation of the flashlight affordance  1907  causes the electronic device to load a flashlight application. In some examples, activation of the camera affordance  1908  causes the electronic device  1900  to load a camera application. 
     In some examples, after (e.g., in response to) transitioning to the moderate power state, the electronic device  1900  initiates biometric authentication (e.g., facial recognition authentication). In some examples, initiating biometric authentication includes obtaining (e.g., capturing with the one or more biometric sensors) data corresponding to at least a portion of the biometric feature of a user. In some examples, when a face (of the user) is detected, the biometric authentication confirms (the user&#39;s) attention and intent to unlock by detecting that the user&#39;s eyes are open and directed at the device. 
     With reference to  FIGS. 19E-G , if the electronic device  1900  determines that the biometric authentication is successful, the electronic device transitions from the moderate power state to a high-power state (e.g., display not dimmed). For example, in  FIG. 19D , the display the electronic device  1900  is in the moderate power state, and in response to successful biometric authentication, the electronic device  1900  gradually increases brightness of the display  1902  over a predetermined period of time, as shown in  FIGS. 19E-G . In some examples, the brightness of the display  1902  is increased according to a function, such as a linear function. 
     In some examples, while transitioning from the moderate power state to the high-power state, the electronic device  1900  displays an unlocked interface  1920 . In some examples, while displaying the unlocked interface  1920 , the electronic device displays an animation indicating that the electronic device is transitioning to the high-power state. As illustrated in  FIGS. 19E-G , while transitioning, the electronic device displays an animation in which the locked state  1912  indicator transitions into an unlocked state indicator  1922  ( FIG. 19G ). In some examples, displaying the animation includes displacing and/or increasing the size of the locked state indicator  1912  to display the unlocked state indicator  1913  ( FIG. 19E ), and raising and rotating a latch of the unlocked state indicator to display the unlocked state indicators  1921  ( FIG. 19F ) and  1922  ( FIG. 19G ), respectively. In some examples, a degree of blurring of one or more objects of the locked state interface  1910  and/or the unlocked state interface  1920  is changed during the animation. In some examples, the electronic device  1900  further outputs a tactile output  1926  while, or in response, to transitioning to the high-power state ( FIG. 19G ). 
     In some examples, the high-power state is an unlocked state. Accordingly, while operating in the high-power state, the electronic device  1900  operates in an unsecured manner (e.g., secured data is accessible to the authenticated user). By way of example, as illustrated in  FIG. 19G , while operating in the high-power state, the electronic device displays contents of the message associated with the notification  1914 . 
     In some examples, to improve unlock performance and keep pace with the natural changes of the user&#39;s face and look, the biometric authentication (e.g., facial recognition authentication) augments its stored mathematical representation over time. In some examples, upon a successful unlock, the biometric authentication optionally uses the newly calculated mathematical representation—if its quality is sufficient—for a finite number of additional unlocks before that data is discarded. In some examples, if the biometric authentication fails to recognize the user, but the match quality is higher than a certain threshold and the user immediately (e.g., within a predefined threshold amount of time) follows the failure by entering an alternative authentication (e.g., passcode, password, pattern, fingerprint), the device takes another capture of biometric data (e.g., via one or more cameras or other biometric sensors capturing facial recognition data) and augments its enrolled biometric authentication (e.g., facial recognition authentication) data with the newly calculated mathematical representation. In some examples, this new biometric authentication (e.g., facial recognition authentication) data is, optionally, discarded after a finite number of unlocks and if the user stop matching against it. These augmentation processes allow biometric authentication (e.g., facial recognition authentication) to keep up with dramatic changes in the user&#39;s facial hair or makeup use, while minimizing false acceptance. 
     With reference to  FIGS. 19E-G , if the electronic device  1900  determines that the biometric authentication was unsuccessful, the electronic device  1900  does not transition to the high-power state, and in some examples remains in the moderate power state. In some examples, while the electronic device  1900  remains in the moderate power state, the electronic device  1900  remains in a locked state. To indicate that the biometric authentication failed, the electronic device  1900  simulates a shake of the locked state indicator  1912 , for instance, by alternating a position of the locked state indicator  1912  between two positions on the locked state interface  1910 . In some examples, the electronic device  1900  further outputs a tactile output  1918  to indicate that the biometric authentication was unsuccessful. 
     As described, while in the moderate power state, the electronic device  1900  is in a locked state, and as a result, secured data on the electronic device is not accessible while the electronic device is in the moderate power state. By way of example, in  FIG. 19I , the electronic device detects a user input  1930  near an edge of the display  1902 . As illustrated in  FIGS. 19I-K , the user input  1930  is a swipe gesture that, in some examples, is a request to access a home screen interface of the electronic device  1900 . However, because the electronic device  1900  is in the moderate power and locked state, in response to the swipe gesture, the electronic device  1900  slides the locked state interface  1910  in an upward direction to display (e.g., reveal) an alternative authentication interface  1932 , with which the user authenticates using an alternative form of authentication than that associated with the biometric feature (e.g., password authentication). The alternative authentication interface  1932  includes a locked state indicator  1934  and a prompt  1936  indicating to the user that entering a valid passcode results in the electronic device  1900  being unlocked (and optionally, transitioned to the high-power state). 
     In some examples, the alternative form of authentication (e.g., passcode, password, or pattern) is required to unlock the device in certain circumstances. In some examples, the alternative form of authentication is required if the device has just been turned on or restarted. In some examples, the alternative form of authentication is required if the device has not been unlocked for more than a predetermined amount of time (e.g., 48 hours). In some examples, the alternative form of authentication is required if the alternative form of authentication has not been used to unlock the device in a predetermined amount of time (e.g., 156 hours). In some examples, the alternative form of authentication is required if the alternative form of authentication has not been used to unlock the device for a predetermined amount of time (e.g., six and a half days) and biometric authentication (e.g., facial recognition authentication) has not been used to unlock the device in a past predetermined amount of time (e.g., the last 4 hours). In some examples, the alternative form of authentication is required if the device has received a remote lock command. In some examples, the alternative form of authentication is required after five unsuccessful attempts to match a face (via facial recognition authentication) on the device. In some examples, the alternative form of authentication is required after initiating power off/Emergency SOS, and then canceling the power off/Emergency SOS, on the device. 
     With reference to  FIGS. 19L-19M , a valid passcode (or password) is received by the electronic device  1900 , at least in part, in response to the tap gesture  1938  ( FIG. 19L ), and optionally, one or more other inputs indicating additional alphanumeric digits of the valid passcode. As shown in  FIG. 19N , once a valid passcode has been received, the electronic device is unlocked and displays (e.g., replaces display of the alternative authentication interface with) the home screen interface  1933 . 
     In  FIGS. 19O-R , the device is operating in the high power (e.g., unlocked) state, and receives an input that is a request to access secured data on the electronic device  1900 . By way of example, as shown in  FIG. 19O , the electronic device  1900  is operating in the high-power state, and as illustrated in  FIG. 19P  receives a swipe gesture  1944  that is a request to access a home screen interface of the electronic device  1900 . As further illustrated in  FIGS. 19P-R , in response to the swipe gesture  1944 , the electronic device  1900  slides the unlocked state interface  1920  in an upward direction to display (e.g., reveal) a home screen interface  1946 . 
       FIGS. 19S-U  illustrate various ways in which the electronic device is transitioned from the high power (e.g., unlocked state) to a locked state, such as the moderate power state or the low power state. In  FIG. 19S , while displaying the unlocked state interface  1920  (as described at least with respect to  FIG. 19G ), the electronic device  1900  receives activation of the unlocked state indicator  1922 . Activation of the unlocked screen indicator  1922  is a tap gesture  1948  in some examples. As shown in  FIG. 19V , in response to the activation of the unlocked state indicator  1922 , the electronic device transitions to the moderate power state and, optionally, displays the locked state indicator  1912  and/or provides a tactile output  1952 . In some examples, while transitioning to the moderate power state, the electronic device displays an animation indicating that the electronic device  1900  is transitioning to the moderate power state (or the low power state). 
     In  FIG. 19T , while displaying the home screen interface  1946 , and while in a high power, unlocked state, the electronic device  1900  receives activation of the button  1904 . Activation of the button  1904 , in some examples, is a press and/or depress of the button  1904 . In response to the activation of the button  1904 , the electronic device transitions to the low power state (as described at least with reference to  FIG. 19B ). In  FIG. 19U , while displaying the home screen interface  1946 , the electronic device  1900  receives activation of an unlocked screen indicator  1950  of the home screen interface  1946 . Activation of the unlocked screen indicator  1922  is a tap gesture  1950  in some examples. In response to the activation of the unlocked state indicator  1922 , the electronic device transitions to the moderate power state and, optionally, displays the locked state indicator  1910  ( FIG. 19V ). 
     In  FIG. 19W , the electronic device  1900  displays a device settings interface  1954 . The device settings interface includes a gaze enablement setting  1955 , which, when enabled, requires the user to be looking at the device for successful biometric authentication. When the setting is disabled, biometric authentication can be successful even if the authorized user is not looking at the device. The device settings interface  1954  further includes a biometric authentication enablement setting  1956 , which, when enabled, enables biometric authentication on the electronic device  1900 . When the biometric authentication enablement setting  1956  is disabled, biometric authentication is not available on the electronic device  1900 . 
     For example, in  FIG. 19W , the electronic device  1900  receives activation of the biometric authentication enablement setting  1956 . The activation of the biometric authentication enablement setting  1956  is a tap gesture  1958  in some examples. Because the biometric authentication enablement setting  1956  is enabled as shown in  FIG. 19W , the biometric authentication enablement setting  1956  is disabled in response to the tap gesture  1958 , as shown in  FIG. 19X . In some examples, as a result, any request to access secured data on the electronic device  1900  requires a user authenticate using an alternative form of authentication. As an example, with reference to  FIGS. 19Y-Z , the electronic device  1900  detects a user input  1930  near an edge of the display  1902 . As illustrated in  FIGS. 19I-K , the user input  1930  is a swipe gesture that, in some examples, is a request to access a home screen interface of the electronic device  1900 . With reference to  FIG. 19AA , Because biometric authentication enablement setting  1956  is disabled, the electronic device  1900 , in response to the swipe gesture  1930 , slides the locked state interface  1910  in an upward direction to display (e.g., reveal) an alternative authentication interface  1932 , with which the user can provide a passcode to unlock the electronic device  1900 . 
     In some examples, one or more elements displayed by the electronic device  1900  are based on context. As illustrated in  FIG. 19AB , for example, a locked state indicator displayed by the electronic device is, in some instances, based on location and/or type of the electronic device  1900 . 
       FIGS. 20A-20F  are a flow diagram illustrating a method for performing biometric authentication using an electronic device in accordance with some examples. Method  2000  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1900 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric feature by the one or more biometric sensors. Some operations in method  2000  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  2000  provides an intuitive way for performing authentication of biometric features. The method reduces the cognitive burden on a user for performing authentication of biometric features, thereby creating a more efficient human-machine interface and intuitive user experience. For battery-operated computing devices, enabling a user to manage authentication of biometric features faster and more efficiently conserves power and increases the time between battery charges. 
     In some examples, prior to detecting that device wake criteria have been met, the electronic device performs a biometric enrollment process. In some examples, during the biometric enrollment, the device required that a face being enrolled include facial characteristics indicative of the face looking at the electronic device during enrollment of the face in order to proceed with the biometric enrollment of the face. In some examples, the device outputs tactile, audio, and/or visual warnings during enrollment if the face is not looking at the electronic device during the enrollment. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1900 ) detects ( 2002 ) that device wake criteria have been met. In some examples, in response to detecting that the device wake criteria have been met, the electronic device transitions ( 2004 ) the electronic device from a first visual state (e.g., low power state) to a second visual state (e.g., moderate power state). Transitioning from the first visual state (e.g., low power state) to the second visual state (e.g., moderate power state) in response to detecting that the device wake criteria have been met allows the user to bypass providing one or more inputs to transition the device from the first state to the second state by manually providing one or more inputs. Performing an operation (automatically) when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the wake criteria is met when the electronic device is lifted, on press of a button (e.g.,  1904 ), and/or on display of a notification (e.g.,  1914 ). In some examples, the first visual state is a display-off state, or a state in which the display of the electronic device is at 10% of maximum brightness state. In some examples, the second visual state is a display brightness state higher than the first visual state (e.g., 10% if the display was off in the first state; 20% if the display was at 10% in the first state). In some examples, the second visual state includes a first introductory screen (e.g.,  1910 ) displayed at first brightness ( 2006 ). In some examples, while in the second visual state, the electronic device displays ( 2010 ) a fourth user interface object (e.g.,  1912 ) indicative of a visual state of the electronic device. In some examples, while in the second visual state, the electronic device displays ( 2012 ) a fifth user interface object (e.g.,  1912 ) indicative of a visual state of the electronic device. In some examples, one or more features (e.g., display (e.g.,  1902 ), the one or more biometric sensors (e.g.,  1903 ), microphone, access to sensitive data such as the contents of messages and applications, the ability to perform destructive actions such as deleting photos or communications, and the ability to perform communication operation such as sending a new message and sharing content stored on the device) of the electronic device are disabled (e.g., powered off or operating with reduced functionality) while the electronic device is in the first visual state ( 2008 ) (e.g., while the device is in the locked state). In some examples, transitioning to the second visual state includes enabling the one or more disabled functions of the electronic device. In some examples, transitioning to the second visual state includes the device into a state in which the one or more disabled components of the electronic device are enabled. In some examples, enabling one or more disabled functions includes enabling the display (e.g.,  1902 ), the one or more biometric sensors (e.g.,  1903 ), and/or the microphone of the electronic device. 
     In some examples, after transitioning the device to the second visual state ( 2014 ), when determining whether biometric authentication criteria have been met, in accordance with a determination that a selectable option (e.g.,  1955 ) of the electronic device is enabled, the electronic device uses a first set of criteria as the biometric authentication criteria. When determining whether biometric authentication criteria have been met, using a first set of criteria as the biometric authentication criteria in accordance with the determination that a selectable option (e.g.,  1955 ) of the device is enabled allows the user easily provide authentication information to the device with minimal input. Performing an operation (automatically) when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the first set of criteria include a requirement that a face of a user was looking at the display of the electronic device (e.g., when determining whether to unlock the device and/or transition from the second visual state to the third visual state). In some examples, further after transitioning the device to the second visual state, when determining whether biometric authentication criteria have been met, in accordance with a determination that the selectable option of the electronic device is not enabled, the electronic device uses a second set of criteria as the biometric authentication criteria. In some examples, the second set of criteria do not include a requirement that the face of the user was looking at the display of the electronic device (e.g., when determining whether to unlock the device and/or transition from the second visual state to the third visual state). In some circumstances, a user enables, for instance using an accessibility option, a gaze detection requirement (e.g.,  1955 ) in which the user is required, by the device, to look at the device during biometric authentication in order for the user&#39;s face to be recognized by the device. 
     In some examples, after transitioning to the second state, the electronic device determines ( 2016 ), by the one or more biometric sensors, whether biometric capture criteria are met. In some examples, the electronic device determines whether a biometric feature is present, for instance, in a field of view of the one or more biometric sensors. In some examples, determining whether biometric capture criteria are met includes determining ( 2018 ) whether the biometric capture criteria are met a first predetermined amount of time after transitioning to the second visual state. In some examples, the electronic device detects the biometric feature immediately after transitioning to the second state. In some examples, the electronic device detects the biometric feature a period of time after transitioning to the second state. In some examples, in accordance with a determination that the biometric capture criteria are met, the electronic device provides ( 2020 ), by the one or more biometric sensors, biometric data associated with a biometric feature. In some examples, once the electronic device has transitioned to the second visual state (recall that the one or more biometric sensors are enabled prior to, or during, this transition), the electronic device uses the enabled one or more biometric sensors to capture the biometric data. 
     In some examples, in accordance with a determination that biometric authentication criteria has been met based on biometric data provided by the one or more biometric sensors (e.g., a biometric feature, such as a face, is authenticated by the device), the electronic device transitions ( 2022 ) the electronic device from the second visual state to a third visual state (e.g., high-power state). Transitioning the device form a second visual state (e.g., a moderate power sate) to a third visual state (e.g., high-power state) in accordance with the determination that biometric authentication criteria has been met based on the biometric data provided by the one or more biometric sensors allows the user to bypass providing one or more inputs to transition the device from the second state to the third state by manually providing one or more inputs. Performing an operation (automatically) when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently 
     In some examples, while the electronic device is in the third visual state, the display of the electronic device is on at a second, relatively high brightness. In some examples, the transition from the second visual state to the third visual state is a continuation of the transition from the first visual state to the second visual state ( 2024 ). In some examples, during the transitions from the first visual state to the second visual state, and from the second visual state to the third visual state, the display continues to brighten from off, to a low brightness, and finally, in response to authentication, to a high brightness. In some examples, the transition to the second visual state transitions to a particular brightness and the transition from the second visual state to the third visual state transitions starting from the particular brightness. In some examples, each increase is made according to a same function. In some examples, the transition to the second visual state includes enlarging at least a respective user interface element (e.g.,  1912 ) displayed in the first visual state and the transition to the third visual state includes further enlarging the respective user interface element (e.g.,  1912 ,  1913 ,  1921 ). In some examples, the second visual state indicates that the device is in a locked state and the third visual state indicates that the device is in an unlocked state. 
     In some examples, further in accordance with a determination that biometric authentication criteria has been met based on biometric data provided by the one or more biometric sensors, the electronic device displays ( 2026 ) an unlock animation including the fifth user interface object (e.g.,  1912 ). Displaying the unlock animation including an user interface object (e.g., the fifth user interface object  1912 ) in accordance with the determination that the biometric authentication criteria has been met based on the biometric data provided by the one or more biometric sensors provides visual feedback by allowing the user to quickly recognize that the authentication was successful and thus that the device has been unlocked. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the fifth user interface objection is a lock. In some examples, the unlock animation is based on context of the electronic device, such as location or type. In some examples, the fifth user interface object (e.g.,  1912 ,  1922 ) has a first (e.g., locked) state when the electronic device is in the second visual state and has a second (e.g., unlocked) state when the electronic device is in the third visual state ( 2028 ). In some examples, the visual state element transitions from the first state to the second state during the unlock animation (animation including  1912 ,  1913 ,  1921 ,  1922 ) ( 2030 ). In some examples, to demonstrate that biometric authentication has succeeded, the electronic device displays an animation (animation including  1912 ,  1913 ,  1921 ,  1922 ) in which a lock unlocks. 
     In some examples, the third visual state includes a second introductory screen at a second brightness, higher than the first brightness ( 2032 ). In some examples, the first introductory screen (e.g.,  1910 ) and the second introductory screen (e.g.,  1920 ) are a same screen, except for the degree of brightness of each screen. 
     In some examples, transitioning from the second visual state to the third visual state includes adjusting ( 2034 ) (e.g., increasing) a size of a first user interface object (e.g.,  1912 ) displayed on the display of the electronic device. In some examples, the electronic device adjusts size of all displayed user interface objects. In some examples, the electronic device adjusts size of less than all displayed user interface elements. In some examples, the first user interface object (e.g.,  1912 ) is a lock icon and the adjusting the size of the first user interface object includes increasing ( 2036 ) the size of the first user interface object. In some examples, transitioning from the second visual state to the third visual state includes changing a degree of blurring of a second user interface object displayed on the display of the electronic device. In some examples, one or more blur parameters, such as a blur radius and/or a blur magnitude, of one or more displayed user interface objects (e.g., wallpaper) are increased and/or decreased. In some examples, blur parameters of all user interface objects are changed. In some examples, blur parameters for less than all user interface objects are changed. In some examples, the first user interface object and the second user interface object are a same element. In some examples, transitioning from the second visual state to the third visual state includes translating a position (e.g., shifting a position; shifting a position without rotating) of a third user interface object displayed on the display of the electronic device from a first position to a second position. In some examples, the lock icon is moved closer to an edge of the display of the electronic devices prior, or during, to the unlocking animation). In some examples, transitioning the device from the second state to the third visual state includes outputting a tactile output (e.g.,  1926 ). In some examples, the electronic device outputs a tactile output indicating the biometric authentication criteria has been met while displaying the unlock animation. 
     In some examples, the third visual state corresponds to an unlocked state ( 2038 ). In some examples, while in third visual state (e.g., while the device is unlocked), the electronic device receives ( 2040 ) a locking input (e.g.,  1948 , press of the button  1904 ,  1952 ). In some examples, the locking input is a press of button (e.g.,  1904 ), such as hardware button, or is a selection of affordance (e.g.,  1922 ,  1950 ) indicating an intent to lock the electronic device. Further, while in the third visual state, in response to receiving the locking input, the electronic device transitions ( 2042 ) from the third visual state to a locked state. In some examples, the device is locked in response to one or more particular inputs. 
     In some examples, while in the locked state, the device is prevented from performing one or more operations that are available in the unlocked state (e.g., displaying a home screen, displaying content of notifications, launching applications, sending communications). Preventing the device from performing one or more operations that are available in the unlocked state while in the locked state enhances device security by prohibiting certain functions or operations to be performed on the device when the device is in the locked state as opposed to in the unlocked state. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, the electronic device displays ( 2044 ) a lock animation including a sixth user interface object (e.g.,  1912 ,  1922 ) indicative of a visual state of the electronic device. Displaying the lock animation including a particular user interface object (e.g., the sixth user interface object,  1912 ,  1922 ) provides visual feedback by allowing the user to quickly recognize that the device is in a locked state. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, the sixth user interface object is a lock. In some examples, the sixth user interface object has a first appearance (e.g., an open lock) when the electronic device is in the third visual state and has a second appearance (e.g., a closed lock) when the electronic device is in the locked state ( 2046 ). In some examples, the sixth user interface object transitions from the first appearance to the second appearance during the lock animation ( 2048 ). In some examples, to demonstrate that the electronic device has been locked, the electronic device displays an animation in which a lock locks. In some examples, transitioning the device from the third visual state to a locked state includes outputting ( 2050 ) a tactile output (e.g.,  1952 ). In some examples, the tactile output includes a single tap. In some examples, the tactile output includes multiple taps. In some examples, the tactile output is timed to synchronize with an animation of the sixth user interface object moving back and forth (e.g., the lock shaking back and forth). In some examples, displaying the lock animation includes displaying a current time. In some examples, the electronic device displays a time when transitioning to a locked state). 
     In some examples, the biometric authentication criteria include a requirement that a user was looking at the display of the electronic device with a face that is consistent with one or more authorized faces. Including the requirement that the user was looking at the display of the device with a face that is consistent with one or more authorized faces for the biometric authentication criteria enhances device security by allowing the authentication to be successful only by (the faces of) authorized users of the device. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. In some examples, unlocking the electronic device requires that the user is looking at the electronic device. 
     In some examples, in accordance with a determination that biometric authentication criteria have not been met based on biometric data provided by the one or more biometric sensors ( 2052 ), the electronic device maintains ( 2054 ) the electronic device in the second visual state. Maintaining the device in the second visual state in accordance with the determination that the biometric authentication criteria have not been met based on the biometric data provided by the one or more biometric sensors enhances device security by prohibiting the device from transitioning to a state that requires authentication without satisfying the proper authentication criteria. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, if the biometric feature is not authenticated, the display of the device is not further brightened as it is in response to authentication of the biometric feature. In some examples, when the biometric authentication criteria have not been met before the device receives an explicit request (e.g.,  1930 ) to unlock the device (e.g., a swipe gesture from a lower portion of the device, a press of a home button, or other input that indicates that the user would like to view and/or interact with content that is not available when the device in the locked state), the device displays an unlock interface (e.g.,  1932 ) while attempting to authenticate the user via one or more forms of authentication such as biometric authentication, passcode authentication, password authentication, pattern authentication, or the like. Examples of authenticating a user in response to a request to unlock the device via different forms of authentication are described in greater detail with reference to  FIGS. 26A-26AS . In some examples, further in accordance with a determination that biometric authentication criteria has not been met based on biometric data provided by the one or more biometric sensors, the electronic device alternates ( 2056 ) a position of the fourth user interface object (e.g.,  1912 ) between a first position and a second position. In some examples, to demonstrate that biometric authentication has failed, the electronic device shakes a lock icon displayed in the introductory interface. In some examples, a tactile output (e.g.,  1918 ) is provided in combination with the shaking lock icon. In some examples, no tactile output is provided. 
     In some examples, while the device is in an unlocked state, the electronic device detects that a locking condition has been met. In some examples, in response to detecting that the locking condition has been met, in accordance with a determination that the locking condition is an explicit lock input (e.g.,  1922 , press of button  1904 ,  1952 ) (e.g., pressing a power button, tapping on a lock icon, etc.), the electronic device transitions the device from the unlocked state to a locked state and outputs a respective lock indication (e.g.,  1912 ). In some examples, the respective lock indication includes a visual, audio, and/or tactile output that indicates that the device has transitioned from the unlocked state to the locked state. In some examples, further in response to detecting that the locking condition has been met, in accordance with a determination that the locking condition is an implicit lock condition (e.g., a covering of a proximity sensor, a long time period without receiving an input, etc.), the electronic device transitions the device from the unlocked state to the locked state without outputting the respective lock indication. 
     In some examples, after detecting that the device wake criteria have been met, the electronic device detects a request to display a biometric authentication setting interface. In some examples, the request to display a biometric authentication setting interface includes a swipe from an edge of the display to display a control panel user interface that includes a plurality of controls including a control associated with enabling or disabling biometric authentication, a long press of one or more hardware buttons that causes the device to display a setting user interface that includes one or more controls including a control associated with enabling or disabling biometric authentication, or navigation through one or more menus in a settings app to a set of controls associated with biometric authentication including one or more controls including a control associated with enabling or disabling biometric authentication. In some examples, in response to the request to display the biometric authentication setting interface, the electronic device displays a biometric authentication setting interface (e.g.,  1954 ). In some examples, while displaying the biometric authentication setting interface, the electronic device receives a first user input (e.g.,  1958 ) corresponding to a request to disable biometric authentication. In some examples, in response to receiving the first user input, the electronic device disables biometric authentication. In some examples, while biometric authentication is disabled and while the device is in a locked state, the electronic device receives a request to unlock the device. In some examples, in response to receiving the request to unlock the device, the electronic device outputs a prompt (e.g., “enter passcode to unlock” as shown in  FIG. 19AA ) for authentication with a different form of authentication from the biometric authentication. In some examples, the different form of authentication is a passcode, a password, fingerprint, etc. 
     In some examples, in accordance with a determination that the biometric capture criteria are not met a first predetermined amount of time after transitioning to the second visual state, the electronic device determines whether the biometric capture criteria are met a second predetermined amount of time after the first predetermined amount of time has elapsed. In some examples, delays between attempts to detect a biometric feature becomes increasingly longer. In some examples, once a biometric authentication attempts threshold has been reached, biometric authentication is disabled. 
     Note that details of the processes described above with respect to method  1200  (e.g.,  FIGS. 20A-20F ) are also applicable in an analogous manner to the methods described herein. For example, method  2000  optionally includes one or more of the characteristics of the various methods described herein with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  1800 ,  2200 ,  2500 , and  2700 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to  FIGS. 19A-H . For another example, one or more interstitial interfaces described in methods  2700  optionally are displayed response to receipt of an input prior to completion of a biometric authentication process. For brevity, these details are not repeated herein. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 20A-20F  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, detecting operation  2002 , transitioning operation  2004 , and transitioning operation  2022 , are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 21A-21AQ  illustrate exemplary user interfaces for biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary example of the user interfaces illustrated in  FIGS. 21A-21AQ  are used to illustrate the processes described below, including the processes in  FIGS. 22A-22F . 
       FIG. 21A  illustrates an electronic device  2100  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary example illustrated in  FIGS. 21A-21AQ , electronic device  2100  is a smartphone. In other examples, electronic device  1500  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  2100  has a display  2102 , one or more input devices (e.g., touchscreen of display  2102 , a button  2104 , a mic), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  2103 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  2103  are the one or more biometric sensors  703 . In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIGS. 21A-C , the electronic device  2100  performs a biometric authentication with a user of the electronic device  2100 . With reference to  FIG. 21A , the electronic device  2100  is in a locked state. As illustrated, in some examples, while in the locked state, the display  2102  of the electronic device  2100  is disabled. In other examples, while in the locked state, the display  2102  of the electronic device  2100  is enabled, and the electronic device  2100  displays a locked state interface (e.g., locked state interface  2110  of  FIG. 21C ) indicating that the electronic device  2100  is in the locked state. While the device  2100  is in the locked state, the electronic device initiates biometric authentication. In  FIG. 21B , the electronic device  2100  initiates biometric authentication in response to detecting a wake condition (e.g., the user moving the device in a predetermined manner). It will be appreciated that the electronic device initiates biometric authentication in response to any number of wake conditions, including but not limited to, movement (e.g., lifting) of the device, press of a button of the device, or touch of the display  2102 . 
     In some examples, initiating biometric authentication includes obtaining (e.g., capturing with the one or more biometric sensors  2103 ) data corresponding to at least a portion of the biometric feature of a user. In response to initiating biometric authentication, the electronic device  1500  obtains (e.g., captures) and processes (e.g., analyzes) the biometric data, for instance to determine, based on the biometric data, whether the biometric feature (or a portion thereof) satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template). In some examples, biometric authentication requires that a user is looking at the device during biometric authentication. Accordingly, as illustrated in  FIG. 21B , the gaze  2106  of a user is directed at the electronic device when the user lifts the device  2100 . 
     In  FIG. 21C , the electronic device  2100 , in response to the wake condition, displays a locked state interface  2110  including a locked state indicator  2112 . In some examples, while displaying the locked state interface  2110 , the electronic device  2100  further displays a flashlight affordance  2107  and a camera affordance  2108 . In some examples, activation of the flashlight affordance  2107  causes the electronic device to load a flashlight application. In some examples, activation of the camera affordance  2108  causes the electronic device  2100  to load a camera application. 
     In  FIG. 21D , the electronic device  2100  determines that the biometric authentication was successful, and in response, displays an unlocked state interface  2120 . In some examples, display of the unlocked state interface  2120  includes display of an unlocking animation, as described with reference to  FIGS. 19D-G . While displaying the unlocked state interface  2120 , the electronic device  2100  further displays (e.g., maintains display of) the flashlight affordance  2107  and the camera affordance  2108 . In some examples, the electronic device  2100  outputs a tactile output  2126  in response to determining that the biometric authentication is successful. 
     In  FIG. 21E , the electronic device  2100  determines that the biometric authentication was not successful. In response, the electronic device  2100  maintains display of the locked state interface  2110 . In some examples, the electronic device displays a shake animation in which the locked state indicator  2112  is moved side-to-side to simulate a “shake” effect to indicate that the biometric authentication was unsuccessful. The electronic device  2100  further outputs a tactile output  2118  to indicate that the biometric authentication was unsuccessful. 
     In some examples, one or more operations accessible during display of the locked state interface  2110  do not require authentication, and accordingly the one or more operations can be performed while the electronic device is in the locked state. By way of example, loading the flashlight application in response to activation of the flashlight affordance  2107  does not require authentication. As another example, with reference to  FIG. 21F , in some examples, the electronic device  2100  detects an activation of the camera affordance  2108  while in the locked state. As shown, the activation of the camera affordance  2108  is a tap gesture  2130  on the camera affordance  2108 . In  FIG. 21G , in response to detecting the activation of the camera affordance  2108 , the electronic device  2100  displays (e.g., replaces display of the locked state interface  2110 ), on the display  2102 , a camera application interface  2132  associated with a camera application. 
     With reference to  FIG. 21H , in some examples, while displaying the unlocked state interface  2120 , the electronic device  2100  displays a prompt  2124  indicating that the device is unlocked and/or that providing an input of predetermined type (e.g., swipe gesture) will allow a user to access secured content, such as a home screen interface (e.g., home screen interface  2129  of  FIG. 21I ). For example, as illustrated, the electronic device  2100  detects a user input  2128 , for instance, near an edge of the display  2102 . The user input  2128  is a swipe gesture that, in some examples, is a request to access a home screen interface of the electronic device  2100 , and in response to the swipe input  2128 , the electronic device displays (e.g., replaces display of the unlocked interface  2120  with) the home screen interface  2129  of  FIG. 21I . In some examples, displaying the home screen interface  2129  includes sliding the unlocked state interface  2120  in an upward direction to display (e.g., reveal) the home screen interface  2129 , as analogously described with reference to  FIGS. 19P-R . 
     In  FIG. 21J , the electronic device is in a locked state, for instance, in response to a failed biometric authentication (as described with reference to  FIGS. 21A-C  and  21 E) and displays the locked state interface  2110  while in the locked state. While displaying the locked state interface  2110 , the electronic device  2100  displays a prompt  2133  indicating that the device is locked and/or that providing an input of predetermined type (e.g., swipe gesture) will allow a user to authenticate with (and unlock) the electronic device  2100 . For example, as illustrated, the electronic device  2100  detects a user input  2134 , for instance, near an edge of the display  2102 . The user input  2134  is a swipe gesture that, in some examples, is a request to access a home screen interface of the electronic device  2100 . Because the device is in the locked state (e.g., the user is not authenticated with the electronic device  2100 ), the electronic device displays (e.g., replaces display of the locked interface  2120  with) an alternative authentication interface  2140  in response to the swipe input  2128 , shown in  FIG. 21K . In some examples, the alternative authentication interface  2140  includes a locked state indicator  2142  indicating that the electronic device  2100  is in the locked state. 
     In  FIGS. 21K-M , the electronic device  2100  performs biometric authentication while displaying the alternative authentication interface  2140 . In particular, while displaying the displaying the alternative authentication interface  2140 , the electronic device  2100  detects and/or obtains biometric data of a face. The electronic device  2100  then processes the biometric data to determine if the biometric data satisfies biometric authentication criteria. As shown in  FIG. 21L , the electronic device  2100  displays (e.g., replaces display of the locked state indicator  2142  with) a biometric authentication processing glyph  2144  to indicate that the electronic device is processing biometric data. In  FIG. 21M , the electronic device  2100  determines that biometric authentication performed during display of the alternative authentication interface  2140  is successful. As a result, the electronic device  2100  displays (e.g., replaces display of the biometric authentication processing glyph  2144  with) a biometric authentication success glyph  2146  to indicate that the biometric authentication was successful. In some examples, the electronic device  2100  further completes progress of a passcode progress indicator, and optionally, provides a tactile output  2141  to indicate the successful biometric authentication. 
     Alternatively, with reference to  FIGS. 21N-P , a user inputs a passcode during display of the alternative authentication interface  2140  to authenticate with the electronic device  2100 . As shown in  FIG. 21 , the electronic device  2100  displays the alternative authentication interface  2140 , and as shown in  FIG. 21O , receives a passcode, at least in part, in response to the tap gesture  2148  and, optionally, one or more other inputs indicating additional alphanumeric digits of the passcode. In  FIG. 21P , the electronic device  2100  determines that the passcode is valid and in response displays a notification  2150  indicating that the passcode was valid and that the user is authenticated with the electronic device  2100 . 
     In some examples, in response to entry of a valid passcode, the electronic device  2100  selectively stores and/or updates biometric data. For instance, in response to entry of a valid passcode, the electronic device  2100  obtains biometric data (e.g., facial biometric data), and compares the biometric data to biometric data stored in the electronic device. If, in some examples, the obtained biometric data is sufficiently similar to the stored biometric data, the electronic device stores the obtained biometric data and/or updates the previously stored biometric data to improve biometric authentication. In  FIG. 21P , the electronic device determines that the biometric data, obtained in response to entry of the valid passcode, is sufficiently similar to stored biometric data. In response, the electronic device stores the obtained biometric data and/or updates stored biometric data, and displays an indication  2152  that the biometric data has been updated. In this manner, the electronic device  2100  provides an adaptive biometric authentication. 
     As described with reference to  FIGS. 21A-C , in some examples, the electronic device  2100  performs biometric authentication in response to a wake condition. In some examples, the electronic device receives a request to access secure content (e.g., content requiring authentication for access), such as a swipe gesture requesting access to a home screen, before biometric authentication has completed. Accordingly, with reference to FIGS. Q-S, in response to receiving a request to access secure content, the electronic device  2100  displays interstitial interfaces to indicate that the electronic device has not yet completed biometric authentication. In  FIG. 21Q , the electronic device displays an interstitial interface  2154  including an alternative authentication affordance  2156  and a biometric authentication glyph  2160  indicating initiation of biometric authentication. Activation of the alternative authentication affordance  2156  causes the electronic device to display (e.g., replace display of the interstitial interface  2154  with) an alternative authentication interface (e.g., alternative authentication interface  2140  of  FIG. 21K ) The biometric authentication glyph  2160  is a simulation of a representation of the biometric feature in some examples. 
     Once the electronic device  2100  has obtained biometric data in response to initiating biometric authentication, the electronic device processes the biometric data, as described. In some examples, while the electronic device processes the biometric data, the electronic device displays (e.g., replaces display of the biometric authentication glyph  2160  with) biometric authentication glyph  2162  to indicate that the biometric data is being processed. In some examples, the biometric authentication glyph  2162  includes a plurality of rings, which rotate spherically, for instance, while displayed. 
     In  FIG. 21S , the electronic device  2100  determines that the biometric data satisfies the biometric authentication criteria. In response, the electronic device  2100  displays (e.g., replaces display of the biometric authentication glyph  2162  with) a biometric authentication glyph  2163  in the interstitial interface  2154 , indicating that the biometric authentication was successful. In some examples, the electronic device ceases display of the alternative authentication affordance  2156 . Additionally or alternatively, the electronic device displays (e.g., replaces display of locked state indicator  2161  with) an unlocked state indicator  2122  and/or outputs a tactile output  2164 , indicating the biometric authentication was successful. 
     As described, in some instances, the electronic device receives a request to access secure before biometric authentication has completed. In some examples, the electronic device receives the request after the electronic device has begun to process biometric data, but prior to completing biometric authentication. In such instances, the electronic device optionally displays the interstitial interface  2154  having the biometric authentication glyph  2162 , and omit first displaying the biometric authentication glyph  2160 . 
     In some examples, one or more functions of the electronic device are selectively enabled based on whether a user is looking at the electronic device  2100 . With reference to  FIGS. 21T-Y , in some examples, some functions are disabled with the user is not looking at the electronic device  2100  and enabled when the user is looking at the electronic device  2100 . In  FIG. 21T , a gaze  2165  of a user is not directed at the electronic device  2100 . In response to determining that the gaze  2165  is not directed at the electronic device  2100 , the electronic device  2100  disables respective functions associated with the flashlight affordance  2107  and the camera affordance  2108 , as shown in  FIG. 21U . While the functions associated with the flashlight affordance  2107  and the camera affordance  2108  are disabled (e.g., while the user is not looking at the device  2100 ), the electronic device receives an activation of the camera affordance  2108 . As shown, the activation is a tap gesture  2166  on camera affordance  2108 . Because the function associated with the affordance is disabled, the electronic device forgoes responding to the tap gesture  2166  (e.g., forgoes loading a camera application). 
     In  FIG. 21V , a gaze  2168  of the user is directed at the electronic device. In response to determining that the gaze  2168  is directed at the electronic device  2100 , the electronic device  2100  enables respective functions associated with the flashlight affordance  2107  and the camera affordance  2108 , as shown in  FIG. 21W . In  FIG. 21X , the electronic device  2100  detects an activation of the camera affordance  2108 . As shown, the activation is a tap gesture  2170  on camera affordance  2108 . In response to the activation of the camera affordance  2108 , the electronic device displays (e.g., replaces display of the locked state interface  2110 ), on the display  2102 , a camera application interface  2132  associated with a camera application ( FIG. 21Y ). 
     With reference to  FIG. 21Z , in some examples, the electronic device  2100 , while in a locked state, displays the locked state interface  2110  including a notification affordance  2174 . As described, in response to a wake condition, the electronic device initiates a biometric authentication. While displaying the locked state interface  2110  and prior to completing the biometric authentication, the electronic device  2100  receives a request to access secured content. By way of example, in  FIG. 21AA , the electronic device  2100  detects an activation of the notification affordance  2174 . As shown, the activation of the notification affordance  2174  is a tap gesture  2176 . 
     With reference to  FIG. 21AB , in response to the activation of the notification affordance  2174 , the electronic device  2100  displays (e.g., replaces display of the locked state interface  2110  with) an interstitial biometric authentication interface  2178  having a biometric authentication progress indicator  2182  and an alternative authentication affordance  2180 . In some examples, the biometric authentication progress indicator  2182  includes a biometric authentication glyph, such as the biometric authentication glyph  2183 , that indicates progress of biometric authentication. In some examples, the biometric authentication progress indicator further identifies the secured content associated with the request to access the secured content (e.g., “messages”). Activation of the alternative authentication affordance  2180  causes the electronic device to display an alternative authentication interface, examples of which are described further below. 
     While displaying the interstitial biometric authentication interface  2178 , the electronic device  2100  continues to perform biometric authentication initiated in response to the wake condition. In some examples, initiating biometric authentication includes obtaining (e.g., capturing with the one or more biometric sensors) data corresponding to a biometric feature of a user. With reference to  FIG. 21AC , in response to obtaining data, the electronic device processes the biometric data, for instance to determine, based on the biometric data, whether the biometric feature satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template). While the electronic device  2100  processes the biometric data, the electronic device  2100 , optionally displays (e.g., replaces display of the biometric authentication glyph  2183  with) a biometric authentication glyph  2184  in the interstitial biometric authentication interface  2178 , indicating that the biometric data is being processed. 
     In  FIG. 21AD , the electronic device  2100  determines that the biometric feature satisfies the biometric authentication criteria. In response, the electronic device displays (e.g., replaces display of the biometric authentication glyph  2184  with) a biometric authentication glyph  2185  in the interstitial biometric authentication interface  2178  indicating that the biometric authentication was successful. Additionally or alternatively, the electronic device displays (e.g., replaces display of locked state indicator  2112  with) an unlocked state indicator  2122  and/or outputs a tactile output  2164 , indicating the biometric authentication was successful. 
     As shown in FIGS. AE-AF, in response to determining that the biometric authentication is successful, the electronic device  2100  displays (e.g., replaces display of the interstitial biometric authentication interface  2178  with) a messaging application interface  2194 . In some examples, displaying the messaging application interface  2194  includes sliding the biometric authentication interface  2178  in an upward direction to display (e.g., reveal) the messaging application interface  2194 , as analogously described with reference to  FIGS. 19P-R . 
     FIGS. AG-AI describe the display of an alternative manner in which biometric authentication progress is displayed. As described with reference to  FIG. 21AA  (and as shown in  FIG. 21AG ), the electronic device  2100  receives, while displaying a locked state interface  2110 , a request to access secured content prior to completing biometric authentication. The request is an activation  2176  of a notification affordance  2174  in some examples. In response to the activation  2176  of the notification affordance  2174 , the electronic device maintains display of the locked state interface  2110 . Additionally, as shown in  FIG. 21AH , the electronic device  2100  displays (e.g., replaces display of the locked state indicator  2110 ) with a biometric authentication glyph  2184  to indicate that biometric data is being processed. In  FIG. 21AI , the electronic device determines that the biometric authentication is successful and in response, displays (e.g., replaces display of the biometric authentication glyph  2184  with) the unlocked state indicator  2122 . Optionally, the electronic device  2100  further outputs a tactile output  2193  indicating that the biometric authentication is successful. In some examples, because the electronic device transitions to an unlocked state in response to determining that the biometric authentication is successful, the electronic device  2100  displays (e.g., replaces display of the notification affordance  2174  with) the notification affordance  2175 . In some examples, the notification affordance  2174  identifies secured content (e.g., “John Appleseed . . . meeting where . . . ”). 
     In  FIG. 21AJ , in response to processing the biometric data (as described with reference to FIG. AC), the electronic device determines that the biometric authentication is unsuccessful. In response, the electronic device  2100  displays (e.g., replaces display of the biometric authentication glyph  2184  with) a biometric authentication glyph  2189  in the biometric authentication interface  2178  indicating that the biometric authentication was unsuccessful. Additionally or alternatively, the electronic device alternates a position of the locked state indicator  2112  to simulate a “shake effect” to indicate that the biometric authentication was unsuccessful and/or outputs a tactile output  2193 , indicating the biometric authentication was unsuccessful. 
     While displaying the interstitial biometric authentication interface  2178 , the electronic device detects an activation of the alternative authentication affordance  2180 . The activation of the alternative authentication affordance  2108  is a tap gesture  2192  in some examples. With reference to  FIG. 21AK , in response to activation of the alternative authentication affordance  2180 , the electronic device displays an alternative authentication affordance  2198 . In some examples, the alternative authentication affordance  2198  includes an indicator  2199  that identifies the secured content associated with the request to access the secured content (e.g., “messages”). 
     With reference to  FIGS. 21AL -AM, a valid passcode (or password) is received by the electronic device  2100 , at least in part, in response to the tap gesture  2102 A ( FIG. 21L ), and optionally, one or more other inputs indicating additional alphanumeric digits of the valid passcode. As shown in  FIGS. 21N-21O , once a valid passcode has been received, the electronic device is unlocked and displays (e.g., replaces display of the alternative authentication interface  2198  with) the messaging application interface  2194 . In some examples, displaying the messaging application interface  2194  includes sliding the alternative authentication interface  2198  in an upward direction to display (e.g., reveal) the messaging application interface  2194 , as analogously described with reference to  FIGS. 19P-R . 
     In some examples, in response to determining that biometric authentication was not successful, the electronic device further determines that a threshold number of biometric authentication attempts has been reached. Accordingly, as shown in  FIG. 21AP , the electronic device  2100 , using the biometric authentication progress indicator  2182 , indicates that the threshold has been reached (“Face authentication temporarily disabled”). As described in FIG. AK, while displaying the interstitial biometric authentication interface  2178 , the electronic device detects an activation of the alternative authentication affordance  2180 , and in response to activation of the alternative authentication affordance  2180 , displays the alternative authentication affordance  2198 . If, as shown in  FIG. 21AQ , the electronic device determines that the threshold number of biometric authentication attempts has been reached, the indicator  2199  that identifies that biometric authentication is re-enabled in response to entry of a valid passcode (“Enter passcode to re-enable Face Authentication”). 
       FIGS. 22A-22F  are a flow diagram illustrating a method for performing biometric authentication using an electronic device in accordance with some examples. Method  2200  is performed at a device (e.g.,  100 ,  300 ,  500 ,  2100 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric feature by the one or more biometric sensors. Some operations in method  2200  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  2200  provides an intuitive way for performing authentication of biometric features. The method reduces the cognitive burden on a user for performing authentication of biometric features, thereby creating a more efficient human-machine interface and intuitive user experience. For battery-operated computing devices, enabling a user to manage authentication of biometric features faster and more efficiently conserves power and increases the time between battery charges. 
     In some examples, while the device is in a locked state, the electronic device (e.g.,  2100 ) receives ( 2202 ) a request to perform an operation that does not require authentication. In some examples, in response to the request to perform the operation that does not require authentication, the electronic device performs an operation without waiting for authentication. Performing an operation that does not require authentication without waiting for authentication allows the user to more quickly access the operation without having to provide additional input (e.g., an input instructing the device to proceed). Performing an operation (automatically) when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the request to perform the operation that does not require authentication includes a request (e.g.,  2130 ) to enable a camera of the electronic device and/or accessing a camera function of the device, such as displaying a camera user interface (e.g.,  2132 ) for capturing images and/or videos with the device. In some examples, the operation that does not require authentication includes displaying an application user interface that includes one or more restricted features (e.g., sharing captured photos or video, viewing photos or video that were captured during a previous use of the camera application while the device was unlocked) that are restricted without successful authentication, and the device attempts biometric authentication while displaying the application user interface. Displaying an application user interface that includes one or more restricted features that are restricted without successful authentication provides visual feedback by allowing the user to quickly view which features are currently restricted on the application without proper authentication. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. If the biometric authentication is successful while displaying the application user interface, the restricted features are enabled and if the biometric authentication is unsuccessful, the restricted features remain disabled (e.g., the user is prevented from sharing captured photos or video, viewing photos or video that were captured during a previous use of the camera application while the device was unlocked and is, optionally, prompted to provide authentication in response to an attempt to use any of the restricted features). 
     In some examples, while the electronic device is in a locked state, the electronic device displays, on the touch-sensitive display (e.g.,  2102 ), one or more affordances (e.g.,  2107 ,  2108 ) for performing operations for which authentication is not required (e.g., a flashlight affordance for enabling a flashlight mode of operation in which a light on the device is turned on and/or camera affordance for accessing a camera function of the device such as displaying a camera user interface for capturing images and/or videos with the device). 
     In some examples, while displaying the one or more affordances for performing operations for which authentication is not required, the electronic device detects activation (e.g.,  2130 ) of a respective affordance (e.g.,  2107 ,  2108 ) of the one or more affordances for performing operations for which authentication is not required. In some examples, in response to detecting activation of a respective affordance of the one or more affordances for performing operations for which authentication is not required, in accordance with a determination that a face was looking at the display of the electronic device (e.g., a determination that a face with facial characteristics indicative of the face looking at the electronic device is in view of one or more cameras or one or more biometric sensors of the device) when the activation of the respective affordance was detected, the electronic device performs an operation associated with the respective affordance. Performing an operation associated with a respective affordance in accordance with a determination that a face (e.g., of the user) was looking at the display of the device reduces power usage and improves battery life of the device performing an operation when the device detects that the user is looking at the device (e.g., and not performing the operation if the user is not looking at the device, which optionally indicates that the affordance was unintentionally selected). 
     In some examples, if the flashlight affordance (e.g.,  2107 ) is activated while a face is looking at the display of the electronic device, the electronic device enables a flashlight mode of operation in which a light on the device is turned on and/or if the camera affordance (e.g.,  2108 ) is activated while a face is looking at the display of the electronic device, the electronic device accesses a camera function of the device such as displaying a camera user interface for capturing images and/or videos with the device. In some examples, in accordance with a determination that a face was not looking at the display of the electronic device (e.g., a determination that a face was not detected or a face was detected but with facial characteristics indicative of the face looking away from the electronic device is in view of one or more cameras or one or more biometric sensors of the device) when the activation of the respective affordance was detected, the electronic device forgoes performance of the operation associated with the respective affordance. In some examples, if the flashlight affordance is activated while a face is not looking at the display of the electronic device, the electronic device forgoes enabling a flashlight mode of operation in which a light on the device is turned on and/or if the camera affordance is activated while a face is not looking at the display of the electronic device, the electronic device forgoes accessing a camera function of the device such as displaying a camera user interface for capturing images and/or videos with the device). 
     In some examples, while the electronic device is in a locked state, the electronic device detects a condition (e.g., user raises device  2100  to a position shown in  FIG. 21B ) that is associated with performing a biometric authentication check using a biometric sensor without an explicit input from the user requesting biometric authentication. In some examples, the condition that is associated with performing a biometric authentication check using a biometric sensor without an explicit input from the user requesting biometric authentication includes raising the device and/or pressing a display wake button (e.g.,  2104 ). 
     In some examples, one or more biometric sensors include a contactless biometric sensor (e.g.,  2103 ) (e.g., a facial recognition sensor) configured to capture biometric data associated with biometric features located within a predetermined range of distances from the contactless biometric sensor (e.g.,  2103 ) ( 2204 ). In some examples, the biometric sensor includes a camera. In some examples, the biometric sensor includes a light projector (e.g., an IR flood or a structured light projector). 
     In some examples, the device is restricted from performing more than a predefined number of biometric authentication checks without successful authentication ( 2206 ). Restricting the device from performing more than a predefined number of biometric authentication checks without successful authentication enhances device security by limiting fraudulent authentication attempts on the device. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, successful authentication includes successful authentication by way of biometric authentication or any other form of authentication, such as with a passcode, a password, or a pattern. In some examples, the device performs fewer than the predefined number of biometric authentication checks in response to detecting the condition, so as to reserve at least one biometric authentication check for use in response detecting the request to perform the respective operation. In some examples, the electronic device tracks a number of failed authentication attempts, such as a number of failed sequential failed attempts without an intervening success authentication (e.g., a biometric authentication or other authentication, such as password authentication). In some such examples, if a maximum number of failed attempts has been reached, the device does not perform biometric authentication until successful non-biometric authentication is received. In some examples, a request to perform an operation that requires authentication after the maximum number of failed biometric authentication checks has been reached triggers display of an alternative authentication user interface (e.g., a password, passcode, pattern or other authentication interface). 
     In some examples, while the display (e.g.,  2102 ) of the electronic device is disabled, the electronic device detects ( 2208 ) a display wake condition. In some examples, a display wake condition includes movement of the device in a predefined manner, such as movement of the device by more than a threshold amount, movement of the device into an orientation that is associated with waking the device, activation of a display wake button, or a gesture, such as a tap, on a touch-sensitive surface. 
     In some examples, in response to detecting the condition, the electronic device performs ( 2210 ) a first biometric authentication check. Performing a biometric authentication check in response to detecting a condition (e.g., a wake condition) allows the user to provide authentication information to the device with minimal input and quickly and efficiently in response to the wake condition being detected. Performing an operation (automatically) when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, performing a first biometric authentication check includes capturing ( 2212 ) first biometric data using the one or more biometric sensors. In some examples, the electronic device initiates a first biometric authentication procedure that includes capturing first biometric data using the one or more biometric sensors. In some examples, performing a first biometric authentication check includes, after capturing the first biometric data ( 2214 ) (e.g., in response to capturing the first biometric data or in response to a request to unlock with the device.), in accordance with a determination that the first biometric data satisfies biometric authentication criteria, transitioning ( 2216 ) the device from the locked state to an unlocked state. Transitioning the device from the locked state to an unlocked state in accordance with a determination that the first biometric data satisfies biometric authentication criteria enhances device security by unlocking the device if the authentication process is successful (but, in some examples, prohibiting the device from being unlocked if the authentication is unsuccessful). Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, the electronic device determines whether the first biometric data satisfy the biometric authentication criteria. In some examples, the biometric authentication criteria includes a criterion that is satisfied when the first biometric data matches biometric data (e.g., facial feature data, fingerprint data, iris data) corresponding to an authorized user. In some examples, while in the unlocked state and prior to detecting the request to perform the respective operation, the electronic device outputs ( 2218 ), according to prompt criteria, a prompt (e.g., a visual, audio, or tactile output) that corresponds to instructions to provide the request to perform a respective operation. In some examples, the device is in the unlocked state after detecting the face of an authorized user. In some examples, the electronic device displays instructions (e.g.,  2124 ) to “swipe up” to access a home screen (e.g.,  2129 ). In some examples, the prompt criteria include a requirement that a gaze (e.g.,  2168 ) of a user is directed at the electronic device ( 2220 ). In some examples, the prompt criteria include a requirement that the device detect facial characteristics indicative of the face looking at the electronic device ( 2222 ) (e.g., detection that the gaze of the user is directed at the electronic device) for at least a predetermined amount of time. 
     In some examples, in accordance with a determination that the first biometric data does not satisfy the biometric authentication criteria, the electronic device maintains ( 2224 ) the device in the locked state. Maintaining the device in the locked state in accordance with the determination that the first biometric data does not satisfy the biometric authentication criteria enhances device security by preventing fraudulent and/or unauthorized access to the device. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. In some examples, if biometric data corresponding to a biometric feature does not match a biometric authentication template, the device remains locked in response to the failed authentication. 
     In some examples, after performing the first biometric authentication check, the electronic device detects ( 2226 ), via the device, a request (e.g.,  2134 ,  2176 ) to perform a respective operation without receiving further authentication information from the user. In some examples, detecting, via the device, a request to perform a respective operation without receiving further authentication information from the user includes detecting ( 2228 ) a request to display content that is unavailable for display when the electronic device is in the locked state. In some examples, the user input is an input that requires access to secured data, such as the home screen or an application presenting secured data. In some examples, the request to perform the respective operation includes a swipe gesture on the device, a swipe gesture (e.g.,  2134 ) from an edge of the device, or a press of a home button. In some examples, the request to perform a respective operation includes at least one of: a selection of a notification (e.g.,  2176 ) (e.g., the request to perform a respective operation is a request to display additional information associated with the notification, such as a long look or an application corresponding to the notification); a swipe gesture (e.g., the request to perform a respective operation is an upward swipe on the display of the electronic device; in some examples, the request to perform a respective operation is an upward swipe starting from an edge of the display of the electronic device. In some examples, the swipe is, in particular, a request to display a home screen of the electronic device); movement of the electronic device in a predetermined manner (e.g., the request to perform a respective operation includes lifting the electronic device); and a selection of an affordance ( 2230 ) (e.g., the request to perform a respective operation includes selection of an affordance displayed by the electronic device, including a “lock” affordance displayed when the electronic device is in the locked state). 
     In some examples, while performing the first biometric authentication check, the electronic device receives ( 2232 ) a second request (e.g.,  2134 ) to perform a second operation without receiving further authentication information from the user. In some examples, the second request is a swipe gesture, selection of notification, or the like. In some examples, in response to receiving the second request to perform the second operation ( 2234 ), in accordance with a determination that the second request to perform the second operation was received after determining that the first biometric data does not satisfy the biometric authentication criteria, the electronic device displays ( 2236 ) a second alternative authentication interface (e.g.,  2140 ). In some examples, the second alternative authentication interface is a passcode, password, pattern, or fingerprint authentication user interface, and is displayed without performing the second operation if the biometric authentication has failed at least once. In some examples, in accordance with a determination that the second request to perform the second operation was received prior to evaluating the first biometric data (e.g., prior to determining whether the first biometric data satisfies the biometric authentication criteria), the electronic device displays ( 2238 ) a biometric authentication indicator (e.g.,  2156 ,  2162 ) that includes an indication that biometric authentication is being attempted without displaying the second alternative authentication interface. In some examples, the second alternative authentication interface is a passcode, password, pattern, or fingerprint authentication user interface, and is not displayed and the second operation is not performed if the device has not had time to complete the first biometric authentication attempt. In some examples, if the user swipes up while the electronic device is performing the first iteration of biometric authentication, the electronic device displays an interstitial interface (e.g.,  2154 ) in which the processing status of the biometric authentication is indicated. In some examples, in response to receiving the second request to perform the second operation in accordance with a determination that the second request to perform the second operation was received after determining that the first biometric data satisfies the biometric authentication criteria, the electronic device performs the second operation without displaying the alternative authentication interface (e.g., a passcode, password, pattern, or fingerprint authentication user interface is displayed if the biometric authentication has failed at least once). In some examples, the biometric authentication indicator that is displayed in response to receiving the second request to perform the second operation in accordance with a determination that the second request to perform the second operation was received prior to evaluating the first biometric data includes an indication of an application associated with the notification (e.g.,  2182 ). In some examples, if the user selects a notification while the device is performing the first biometric authentication check, the device indicates the application associated with the notification. By way of example, if the user selects on a message notification, the device displays an indication directed to the messaging application such as “Biometric Authentication for Messages” or “Face ID for Messages”. 
     In some examples, in response to detecting the request to perform the respective operation ( 2240 ), in accordance with a determination that the respective operation does not require authentication, the electronic device performs the respective operation ( 2242 ). Performing a respective operation without successful authentication in accordance with the determination that the respective operation does not require authentication allows the user to more quickly access the operation without having to provide additional input (e.g., an input instructing the device to proceed). Performing an operation (automatically) when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, if an operation does not require authentication, the electronic device performs the operation without regard to whether the device is in a locked state or an unlocked state. In some examples, the device does not check for authentication if the respective operation does not require authentication, such as use of the camera or to place an emergency call. 
     In some examples, in accordance with a determination that the respective operation requires authentication and that the device is in the unlocked state, the electronic device performs the respective operation ( 2244 ). Performing a respective operation in accordance with a determination that the respective operation requires authentication, if the device is in the unlocked state, allows the user to more quickly access the operation without having to provide additional input (e.g., an input instructing the device to proceed). Performing an operation (automatically) when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in accordance with a determination that the respective operation requires authentication and that the device is in the locked state ( 2246 ), the electronic device captures second biometric data using the one or more biometric sensors without an explicit input from the user requesting a second biometric authentication check ( 2248 ). Capturing second biometric data without an explicit input from the user requesting the second biometric authentication check in accordance with the determination that the respective operation requires authentication and that the device is in the locked state enhances device security by requiring successful authentication and thus preventing fraudulent and/or unauthorized access to the device while the device is in a locked state. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, after capturing the second biometric data, the electronic device performs ( 2250 ) the second biometric authentication check. In some examples, the first biometric data and the second biometric data are compared to a same set of biometric criteria. In some examples, the first and second biometric data are compared to respective sets of biometric criteria. In some examples, performing the second biometric authentication check includes, in accordance with a determination that the second biometric data satisfies the biometric authentication criteria, performing ( 2252 ) the respective operation. In some examples, the electronic device, optionally, further transitions the device from the locked state to an unlocked state). In some examples, performing the second biometric authentication check includes in accordance with a determination that the second biometric data does not satisfy the biometric authentication criteria, forgoing ( 2254 ) performance of the respective operation (and, optionally, maintaining the device in the locked state). In some examples, forgoing performance of the respective operation includes maintaining ( 2256 ) the device in the locked state. In some examples, forgoing performance of the respective operation includes displaying ( 2258 ) an alternative authentication user interface (e.g.,  2140 ,  2198 ). In some examples, the alternative authentication interface is a passcode, password, pattern or fingerprint authentication user interface. In some examples, while displaying the alternative authentication user interface, the electronic device detects an alternative authentication attempt (e.g., entry of passcode including tap gesture  2102 A) that corresponds to the alternative authentication user interface. In some examples, the alternative authentication attempt that corresponds to the alternative authentication user interface is an input passcode, input password, input pattern, or fingerprint detected on the fingerprint sensor. In some examples, in response to detecting the alternative authentication attempt that corresponds to the alternative authentication user interface, in accordance with a determination that the authentication attempt is successful (e.g., the provided authentication information is consistent with stored authentication information such as a stored passcode, stored password, stored pattern or stored fingerprint information) and that biometric data corresponding to the alternative authentication attempt (e.g., the second biometric data or biometric data captured while or shortly after the authentication attempt was in progress such as when a last character of a passcode or a password submit button is selected) meets first similarity criteria to stored biometric data that corresponds to an authorized user of the device, the electronic device performs the respective operation. In some examples, the electronic device stores additional information based on the biometric data corresponding to the alternative authentication attempt as biometric data that can be used in future biometric authentication attempts to identify the authorized user of the device. In some examples, the electronic device learns about changes to the user&#39;s face for use in authenticating the user in future authentication attempts). In some examples, further in response to detecting the alternative authentication attempt that corresponds to the alternative authentication user interface, in accordance with a determination that the authentication attempt is successful and that biometric data corresponding to the alternative authentication attempt meets first similarity criteria to stored biometric data that corresponds to an authorized user of the device, the electronic device outputs an output (e.g., visual, audio, and/or tactile output) indicating that information used in future biometric authentication attempts to identify the authorized user of the device (e.g., a biometric template) has been modified. In some examples, the electronic device displays an indication that biometric data has been updated to better recognize the user&#39;s face. 
     In some examples, in accordance with a determination that the authentication attempt is successful (e.g., the provided authentication information is consistent with stored authentication information such as a stored passcode, stored password, stored pattern or stored fingerprint information) and that biometric data corresponding to the alternative authentication attempt (e.g., the second biometric data or biometric data captured while or shortly after the authentication attempt was in progress such as when a last character of a passcode or a password submit button is selected) does not meet the first similarity criteria to stored biometric data that corresponds to an authorized user of the device, the electronic device performs the respective operation. Performing the respective operation in accordance with the determination that the authentication attempt is successful and that the biometric data corresponding to the alternative authentication attempt does not meet the first similarity criteria to stored biometric data provides the user with an alternative method to access operations (e.g., locked operations) of the device that require successful authentication when the biometric data does not correspond to stored biometric data. Providing additional control options with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device does not store additional information based on the biometric data corresponding to the alternative authentication attempt as biometric data that can be used in future biometric authentication attempts to identify the authorized user of the device. In some examples, in response to detecting the alternative authentication attempt that corresponds to the alternative authentication user interface, in accordance with a determination that the authentication attempt is not successful (e.g., the provided authentication information is not consistent with stored authentication consistent with stored authentication information such as a stored passcode, stored password, stored pattern or stored fingerprint information), the electronic device forgoes performing the respective operation and does not store additional information based on the biometric data corresponding to the alternative authentication attempt as biometric data that can be used in future biometric authentication attempts to identify the authorized user of the device. 
     In some examples, in response to detecting the request to perform the respective operation and in accordance with a determination that the respective operation requires authentication and that the device is in the locked state, the electronic device displays an alternative authentication interface. Providing an alternative authentication interface (e.g., to provide an alternative method for providing the authentication, in addition to or alternatively to the biometric authentication) allows the user to easily provide authentication for an operation using a different authentication method if the current authentication method is or continues to be unsuccessful. Providing additional control options (e.g., for providing authentication) in this manner without cluttering the UI with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device displays an alternative authentication interface (e.g.,  2140 ,  2198 ), such as a password or passcode interface, in response to the user requesting access to secured data after the failure of the first iteration of biometric authentication. Displaying the authentication interface, such as the password or passcode interface, in response to the user requesting access to secured data after the failure of the first iteration of biometric authentication provides the user with a quick alternative method to access operations (e.g., locked operations) of the device that require successful authentication when the biometric data is unsuccessful. Providing additional control options with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the alternative authentication interface is displayed after an additional time delay and/or after an additional biometric authentication attempt has failed (e.g., as described in greater detail with reference to  FIGS. 26A-26AS . In some examples, the biometric authentication criteria include a requirement that authentication using the alternative authentication interface has not yet started in order for the biometric authentication criteria to be met ( 2260 ). In some examples, (e.g., in response to) at least partially attempting biometric authentication while displaying the alternative authentication user interface: in accordance with a determination that biometric authentication was successful and authentication using the alternative authentication interface has not started, the electronic device performs the respective operation; and in accordance with a determination that authentication using the alternative authentication interface has started (e.g., a determination that at least a partial credential has been received using the alternative authentication interface, such as a partial passcode, pattern, or password), the electronic device forgoes performing the respective operation based on the biometric authentication. In some examples, the electronic device waits to perform the second biometric authentication until the user has finished providing the passcode). In some examples, the device delays displaying the alternative authentication user interface until after the second biometric authentication check has failed (e.g., as described in greater detail with reference to  FIGS. 26A-26AS ) and the device performs a third biometric authentication check after the alternative authentication user interface has been displayed. 
     In some examples, the second biometric authentication check is performed while displaying an alternative authentication interface (e.g.,  2140 ) ( 2262 ). Performing the second biometric authentication check while displaying the alternative authentication interface enhances the operability of the device by, in some examples, completing the second biometric authentication check prior to the completion of the user providing manual alternative authentication input, thereby making the user-device interface more efficient. 
     In some examples, the alternative authentication interface is a passcode, password, pattern or fingerprint authentication user interface. In some examples, performing the at least a portion of second biometric authentication check includes performing at least a portion of the second biometric authentication check while displaying an alternative authentication interface. In some examples, biometric authentication is performed during passcode entry. In some examples, a biometric authentication UI is displayed on the passcode entry interface (e.g., biometric progress indicators  2142 ,  2144 , and  2146 ). 
     In some examples, while displaying the alternative authentication user interface (e.g., a passcode, password, pattern, or fingerprint authentication user interface), the electronic device determines that the biometric authentication criteria have been met. In some examples, in response to determining that the biometric authentication criteria have been met, the electronic device performs the respective operation. Performing the respective operation in response to determining that the biometric authentication criteria have been met while displaying the alternative authentication user interface enhances the operability of the device by, in some examples, completing the second biometric authentication check prior to the completion of the user providing manual alternative authentication input, thereby making the user-device interface more efficient. In some examples, the biometric authentication criteria includes a requirement that the user has not entered at least a portion of a credential using the alternative authentication interface. In some examples, the biometric authentication criteria includes a requirement that the user has not entered at least a portion of a credential using the alternative authentication interface. In some examples, the respective operation is not performed if there is a successful biometric authentication if the user has already started entering an alternative form of authentication, such as a passcode, password, pattern, or fingerprint. 
     In some examples, in response to detecting the request to perform the respective operation and in accordance with a determination that the respective operation requires authentication and that the device is in the locked state, the electronic device displays an authentication indication for the biometric authentication (e.g., a progress indicator or another indication that the biometric authentication is being attempted) without displaying an option to proceed with an alternative form of authentication. In some examples, the electronic device displays an authentication indication for the biometric authentication without displaying an alternative authentication interface and/or without displaying a selectable option to display an alternative authentication interface. In some examples, while attempting the biometric authentication in response to the request to perform the respective operation, the device forgoes providing options for alternative forms of authentication in order to indicate to the user that the biometric authentication has not yet failed (e.g., as described in greater detail with reference to  FIGS. 26A -AS. 
     In some examples, while the device is in an unlocked state, the electronic device receives a request to store additional information for use in biometric authentication (e.g., in a biometric enrollment user interface in a device settings user interface or a system preferences user interface). In some examples, in response to the request to store additional information for use in biometric authentication, the electronic device captures third biometric data. In some examples, further in response to the request to store additional information for use in biometric authentication, in accordance with a determination that the third biometric data meets second similarity criteria to stored biometric data that corresponds to an authorized user of the device, the electronic device stores additional information based on the third biometric data that can be used in future biometric authentication attempts to identify the authorized user of the device. Storing the additional information based on the third biometric data that can be used in future biometric authentication attempts to identify the authorized user of the device while the device is in an unlocked state (e.g., and prohibiting such an operation while the device is in a locked state) enhances device security prevent fraudulent and/or unauthorized attempts to stored biometric authentication data on the device and thus gain future access to the device. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, the electronic device learns about changes to the user&#39;s face for use in authenticating the user in future authentication attempts. In some examples, the second similarity criteria requires less similarity between the third biometric data and the stored biometric data than is required by the first similarity criteria. In some examples, while the device is in an unlocked state and in a biometric data enrollment user interface, the device is configured to accept additional biometric data that corresponds to a biometric feature that is more different from currently enrolled biometric features than when the device is learning about biometric features detected when alternative authentication is successfully provided after biometric authentication has failed. In some examples, in accordance with a determination that the third biometric data does not meet the second similarity criteria to stored biometric data that corresponds to an authorized user of the device, the electronic device stores additional information based on the third biometric data that can be used in future biometric authentication attempts to identify the authorized user of the device. In some examples, the electronic device learns about changes to the user&#39;s face for use in authenticating the user in future authentication attempts). 
     Note that details of the processes described above with respect to method  1200  (e.g.,  FIGS. 22A-22F ) are also applicable in an analogous manner to the methods described herein. For example, method  2200  optionally includes one or more of the characteristics of the various methods described herein with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  1800 ,  2000 ,  2500 , and  2700 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to  FIGS. 21C-E . For another example, one or more interstitial interfaces as described in methods  2000  and  2700  optionally are displayed in response to receipt of an input prior to completion of a biometric authentication process. For brevity, these details are not repeated herein. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 22A-22F  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, detecting operation  2202 , performing operation  2210 , capturing operation  2212 , transitioning operation  2216 , maintaining operation  2224 , detecting operation  2226 , performing operation  2250 , and forgoing operation  2254  are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 23A-23Q  illustrate exemplary user interfaces for managing biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary example of the user interfaces illustrated in  FIGS. 23A-23Q  relate to the exemplary example of the user interfaces illustrated in  FIGS. 24A-24BC , which in turn are used to illustrate the processes described below, including the processes in  FIGS. 25A-25C . 
       FIG. 23A  illustrates an electronic device  2300  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary example illustrated in  FIGS. 23A-23Q , electronic device  2300  is a smartphone. In other examples, electronic device  2300  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  2300  has a display  2302 , one or more input devices (e.g., touchscreen of display  2302 , a button  2304 , a mic (not displayed)), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  2303 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  2303  are the one or more biometric sensors  703 . In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 23A , electronic device  2300  displays, on display  2302 , a photo gallery user interface  2310 . In some examples, photo gallery user interface  2310  slides into the display from an edge of the display (e.g., slides up from the bottom edge of the display) to replace display of a previous interface, application, and/or virtual keyboard. In some examples, photo gallery user interface  2310  slides up in response to a request to open a photo gallery application. In some examples, photo gallery user interface  2310  slides up in response to a request to transfer photos to a participant of a conversation in a messaging application. 
     In some examples, as shown in  FIG. 23A , photo gallery user interface  2310  includes a plurality of selectable preview images corresponding to photos stored on electronic device  2300  (or accessible by the device via a remote server). In some examples, as also shown in  FIG. 23A , the plurality of selectable preview images are organized based on time (e.g., a date during which a photo was taken) and/or based on location (e.g., of where a photo was taken). For example, the plurality of selectable preview images  2312 A- 2312 F shown under header  2312  correspond to photos taken on April 30 at Cupertino, Calif. and the plurality of selectable preview images  2314 A- 2314 C shown under header  2314  corresponds to photos taken yesterday at San Francisco, Calif. 
     In some examples, upon launching the photo gallery application, electronic device  2300  displays selectable preview images of photo gallery user interface  2310  that can be selected (to be transferred). For instance, the plurality of selectable preview images include selectable preview images  2314 - 2314 C. As shown in  FIG. 23A , plurality of selectable preview images  2314 A- 2314 C can be selected by a user to be transferred to a participant via one or more applications, such as a messaging application or email application. 
     In  FIG. 23B , while displaying photo gallery user interface  2310  with selectable preview images  2314 A- 2314 C (corresponding to photos selected to be transferred), electronic device  2300  detects user activation  2301  of a transfer affordance  2316  (e.g., a button) for initiating transfer of the photos corresponding to selectable preview images  2314 A- 2314 B. For example, user activation  2301  is a tap gesture on transfer affordance  2316 . 
     In  FIG. 23C , in response to detecting the activation of transfer affordance  2316 , electronic device  2300  provides a prompt  2318 . As illustrated in  FIG. 23C , in some examples, prompt  2318  instructs the user to provide one or more activations of button  2304 , such as a double press of button  2304 . In some examples, prompt  2318  is emphasized relative to one or more other displayed objects. Emphasizing the prompt in this manner includes, for instance, darkening, blurring, and/or otherwise obfuscating one or more portions of photo gallery user gallery  2310 . 
     As also illustrated in  FIG. 23C , further in response to detecting the activation of transfer affordance  2316 , electronic device  2300  displays an application selection interface  2320  including a plurality of application affordances  2320 A- 2320 H. In some examples, each of application affordances  2320 A- 2320 H corresponds to an application that can be used for transferring images (to a different device other than electronic device  2300 ), such as images corresponding to selectable preview images  2314 A- 2314 C. 
     In some examples, button  2304  has a fixed position relative to display  2302  and/or one or more other components of electronic device  2300 . In some examples, prompt  2318  is also displayed in a fixed position relative to display  2302  and/or one or more other components of the electronic device. In this manner, prompt  2318  is displayed at a predetermined position relative to button  2304 . 
     In  FIG. 23D , while displaying prompt  2318  (which is optionally overlaid over the photo gallery user interface), electronic device  2300  detects user activation  2306  of button  2304 . In some examples, as shown in  FIG. 23D , the user activation is a double press of button  2304 . In some examples, the double press of button  2304  includes a first press of the button and a second press of the button occurring within a predetermined amount of time (e.g., 1 second). 
     In response to detecting the one or more activations of button  2304 , electronic device  2300  initiates biometric authentication (e.g., facial recognition authentication) for a biometric feature (e.g., face) of the user. As illustrated in  FIG. 23E , in some examples, upon initiation of biometric authentication, a biometric authentication interface  2322  is provided (e.g., is displayed on display  2302 ). In some examples, the biometric authentication interface is overlaid over an application interface, such as photo gallery user interface  2310 , during the biometric authentication. In some examples, the biometric authentication includes a simulation of a representation of the biometric feature, such as a glyph  2324 . Further in response to the one or more activations of button  2304 , one or more biometric sensors  2303  of electronic device  2300 , such as one or more cameras or a facial recognition sensor (e.g., included among one or more biometric sensors  2303 ), are activated. 
     In some examples, once the one or more biometric sensors  2303  are activated, electronic device  2300  obtains (e.g., captures) biometric data corresponding to the biometric feature associated with the user. In some examples, the biometric feature captures the biometric data using the one or more biometric sensors  2303  (and/or biometric sensors of one or more cameras) of the electronic device. Optionally, a light-emitting device, such as an IR flood light or a structured light projector is used to assist in illuminating the biometric feature. In other examples, the electronic device receives the biometric data from another device. 
     In some examples, once electronic device  2300  has obtained the biometric data, the electronic device processes (e.g., analyzes) the biometric data to determine whether the biometric authentication is successful. In some examples, this determination includes determining whether the biometric data matches a biometric template associated with the user. The biometric template is, optionally, stored on electronic device  2300 . 
     In some examples, as illustrated in  FIG. 23F , while processing the biometric data, the biometric authentication interface  2322  indicates that the biometric data is being processed by the electronic device, for instance, by displaying one or more rotating rings  2326  using the biometric authentication interface, as described with reference to  FIGS. 17A -AI. In some examples, one or more rotating rings  2326  replaces glyph  2324  within the biometric authentication interface. 
     If electronic device  2300  determines that biometric authentication is successful (e.g., the biometric data matches a biometric template associated with the user), the electronic device transitions from a state in which a function (e.g., image transfer) is disabled to a state in which the function is enabled. By way of example, successful biometric authentication enables the electronic device to transfer (e.g., share) images, such as images corresponding to selectable preview images  2314 A- 2314 C. In some examples, the electronic device further indicates that the biometric authentication was successful, for instance, by displaying a simulation of a representation of the biometric feature in the biometric authentication interface. As shown in  FIG. 23G , in some examples, biometric authentication interface  2322  includes a glyph  2328  indicating (to the user) that the biometric authentication was successful. In some examples, glyph  2328  replaces one or more rotating rings  2326  within biometric authentication interface  2322 . 
     With reference to  FIG. 23H , after the image transfer has been enabled on electronic device  2300  in response to successful biometric authentication, and while displaying application selection interface  2320 , the electronic device detects user activation  2305  of an application affordance (to launch the corresponding application). For example, the activated affordance is application affordance  2320 A. The activation of application affordance  2320 A launches an application  2330  (e.g., a messaging application) corresponding to application affordance  2320 A and/or causes the electronic device to transfer images corresponding to selectable preview images  2314 A- 2314 C using application  2330  (e.g., simultaneously with the launching of the application), as shown in  FIG. 23I . 
     If electronic device  2300  determines that biometric authentication is unsuccessful (e.g., the biometric data does not match a biometric template associated with the user), the electronic device does not transition between states (e.g., from a state in which a function, such as authorizing the transfer of images, is disabled to a state in which the function is enabled) but maintains a same state. In some examples, the electronic device further indicates (to the user) that the biometric authentication was unsuccessful, for instance, by displaying a simulation of a representation of the biometric feature in the biometric authentication interface. As shown in  FIG. 23J , in some examples, biometric authentication interface  2322  includes a glyph  2332  indicating that the biometric authentication was unsuccessful. Glyph  2332  indicates, for instance, that the biometric feature was not recognized by the electronic device. 
     In  FIG. 23K , after the image transfer has not been enabled on electronic device  2300  in response to the unsuccessful biometric authentication, and while displaying application selection interface  2320 , the electronic device detects user activation  2307  of application affordance  2320 A. In some examples, as shown in  FIG. 23L , in response to detecting the activation of application affordance  2320 A of application selection user interface  2320 , electronic device  2300  displays an alternative authentication affordance  2334  (e.g., a password affordance, a passcode affordance). In some examples, while displaying alternative authentication affordance  2334 , the electronic device detects user activation  2309  of alternative authentication affordance  2334 . The activation of the alternative authentication affordance causes display of an alternative authentication interface  2336  (e.g., a password interface, a passcode interface), as shown in  FIG. 23M . 
     In some examples, electronic device  2300  performs biometric authentication during display of alternative authentication interface  2336 . In some examples, the electronic device obtains and processes biometric data to determine whether the obtained biometric data matches a biometric template associated with the user. As such, in some examples, alternative authentication interface  2336  includes a simulation of a representation of the biometric feature, such as a glyph  2338  (e.g., corresponding to glyph  2324 ), as shown in  FIG. 23M . In some examples, alternative authentication interface  2336  indicates that the biometric data is being processed by the electronic device, for instance, by displaying one or more rotating rings  2340  (e.g., corresponding to one or more rotating rings  2326 ), as shown in  FIG. 23N , and as described with reference to  FIGS. 17A -AI. In some examples, one or more rotating rings  2340  replaces glyph  2338  within the alternative authentication interface. 
     If electronic device  2300  determines that biometric authentication is unsuccessful (e.g., the biometric data does not match a biometric template associated with the user), the electronic device remains in a state in which a function (e.g., the image transfer) is disabled. In some examples, the electronic device further indicates that the biometric authentication was unsuccessful, for instance, by displaying a simulation of a representation of the biometric feature in alternative authentication interface  2336 . As shown in  FIG. 23O , in some examples, alternative authentication interface  2336  includes a glyph  2342  (e.g., corresponding to glyph  2328 ) indicating (to the user) that the biometric authentication was unsuccessful. In some examples, glyph  2342  replaces one or more rotating rings  2340  within the alternative authentication interface. 
     In some examples, in addition to, or instead of, biometric authentication, electronic device  2300  performs passcode authentication during display of alternative authentication interface  2336 . Accordingly, the electronic device receives and processes passcode data to determine whether the received passcode data matches an enrolled passcode associated with the user. As such, in some examples, alternative authentication interface  2336  includes an indication of the received passcode input, such as passcode indication  2344 , as shown in  FIG. 23P . 
     As discussed above, if electronic device  2300  determines that biometric authentication and/or passcode authentication is successful, the electronic device transitions from a state in which a function (e.g., image transfer) is disabled to a state in which the function is enabled. For example, as shown in  FIG. 23Q , successful biometric and/or passcode authentication enables the electronic device to transfer (e.g., share) images, such as images corresponding to selectable preview images  2314 A- 2314 C, via application  2330  (e.g., a messaging application). 
     As mentioned above, the exemplary example of the user interfaces illustrated in  FIGS. 23A-23Q  described above relate to the exemplary example of the user interfaces illustrated in  FIGS. 24A-24BC  described below. Therefore, it is to be understood that the processes described above with respect to the exemplary user interfaces illustrated in  FIGS. 23A-23Q  and the processes described below with respect to the exemplary user interfaces illustrated in  FIGS. 24A-24BC  are largely analogous processes that similarly involve initiating and managing biometric authentication using an electronic device (e.g.,  100 ,  300 ,  500 ,  2300 , or  2400 ). 
       FIGS. 24A-24BC  illustrate exemplary user interfaces for managing biometric authentication, in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIGS. 25A-25C . 
       FIG. 24A  illustrates an electronic device  2400  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary example illustrated in  FIGS. 24A-24BC , electronic device  2400  is a smartphone. In other examples, electronic device  2400  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  2400  has a display  2402 , one or more input devices (e.g., touchscreen of display  2402 , a button  2404 , a mic (not displayed)), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  2403 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 24A , electronic device  2400  displays, on display  2402 , a tutorial user interface  2410 . In some examples, tutorial user interface  2410  slides into the display from an edge of the display (e.g., slides up from the bottom edge of the display) to replace display of a previous interface, application, and/or virtual keyboard. In some examples, tutorial user interface  2410  slides up in response to a request to proceed with a payment transaction (e.g., with a different device, such as a transaction terminal). 
     In some examples, as shown in  FIG. 24A , tutorial user interface  2410  includes a text indication  2410 A indicating to the user that an input (e.g., a double press of button  2404 ) can be performed to proceed with the payment transaction. In some examples, as also shown in  FIG. 24A , tutorial user interface  2410  includes a graphical indication  2410 B, corresponding to text indication  2410 A, indicating (to the user) that an input (e.g., a double press of button  2404 ) can be performed to proceed with the payment transaction. 
     In some examples, in response to detecting user activation of an affordance (e.g., a “continue” affordance) on tutorial user interface  2410 , electronic device  2400  displays, on display  2402 , a pay user interface  2412  that includes a representation of a payment account  2414  currently selected for use in a payment transaction overlaid by a prompt  2416  instructing that the user provide one or more activations of button  2404  (e.g., a double press of button  2404 ), as shown in  FIG. 24B . In some examples, prompt  2416  is emphasized relative to one or more other displayed objects (on pay user interface  2412 ). Emphasizing the prompt in this manner includes, for instance, darkening, blurring, and/or otherwise obfuscating one or more portions of pay user interface  2412 . 
     In some examples, the location of button  2404 , which is requested by prompt  2416  to be activated (e.g., to proceed with a payment transaction), is emphasized by a dynamic indication  2418 . For example, as shown by the transition from  FIG. 24B  to  FIG. 24C , dynamic indication  2418  emphasizes the location of button  2404  on the device by continuously changing in size (e.g., continuously alternating between becoming wider and becoming narrower, or otherwise continuously changing in size) adjacent to the location of button  2404  on the display, thereby allowing the user to more easily locate the button corresponding to the request of prompt  2416 . 
     In  FIG. 24D , while displaying prompt  2416 , electronic device  2400  detects activation  2401  of button  2404 . In some examples, as shown in  FIG. 24D , the activation is a double press of button  2404 . In some examples, the double press of button  2404  includes a first press of the button and a second press of the button occurring within a predetermined amount of time (e.g., 1 second). 
     In response to the one or more activations of button  2404 , electronic device  2400  removes display of prompt  2416  (and any corresponding emphasis of the prompt) and dynamic indication  2418  overlaid on pay user interface  2412 , as shown in  FIG. 24E , and initiates biometric authentication (e.g., facial recognition) for a biometric feature (e.g., face) of the user, as shown in  FIG. 24F . In some examples, a biometric feature is at least part of a face (e.g., the user&#39;s face), and biometric authentication involves facial recognition of at least a portion of the (user&#39;s) face. 
     As illustrated in  FIG. 24F , in some examples, upon initiation of the biometric authentication, a biometric authentication interface  2420  is provided. In some examples, the biometric authentication interface is overlaid over pay user interface  2412  during the biometric authentication. In some examples, the biometric authentication includes a simulation of a representation of the biometric feature, such as a glyph  2422 . Further in response to the one or more activations of button  2404 , one or more biometric sensors of electronic device  2400 , such as one or more cameras or a facial recognition sensor (e.g., included among one or more biometric sensors  2403 ), are activated. In some examples, the electronic device displays biometric authentication interface  2420  at a center region of the display and displays (e.g., by displacing or moving up) representation of the payment account  2414  to a top portion of the display. 
     In some examples, once the one or more biometric sensors are activated, electronic device  2400  obtains (e.g., captures) biometric data corresponding to the biometric feature associated with the user. In some examples, the biometric feature captures the biometric data using one or more biometric sensors  2403  (and/or biometric sensors of the one or more cameras) of the electronic device. Optionally, a light-emitting device, such as an IR flood light or a structured light projector is used to assist in illuminating the biometric feature. In other examples, the electronic device receives the biometric data from another device. 
     In some examples, once electronic device  2400  has obtained the biometric data, the electronic device processes (e.g., analyzes) the biometric data to determine whether the biometric authentication is successful. In some examples, this determination includes determining whether the biometric data matches a biometric template associated with the user. The biometric template is, optionally, stored on electronic device  2400 . 
     In some examples, as illustrated in  FIG. 24G , biometric authentication interface  2420  indicates that the biometric data is being processed by the electronic device, for instance, by displaying one or more rotating rings  2424  using the biometric authentication interface. In some examples, one or more rotating rings  2424  replaces glyph  2422  within the biometric authentication interface. 
     If electronic device  2400  determines that the biometric authentication is successful (e.g., the biometric data matches a biometric template associated with the user), the electronic device transitions from a first state in which a function (e.g., authorization for transmitting payment credentials) is disabled to a second state in which the function is enabled. In some examples, the first state is a state in which a secure element of the device is disabled from releasing secure data (e.g., payment credentials of a payment account provisioned on the device) and the second state is a state in which a secure element is enabled to release the secure data. 
     In some examples, successful biometric authentication authorizes the electronic device to transfer account credentials in connection with a payment transaction. In some examples, the electronic device further indicates (to the user) that the biometric authentication was successful, for instance, by displaying a simulation of a representation of the biometric feature in the biometric authentication interface. As shown in  FIG. 24H , in some examples, biometric authentication interface  2420  includes a glyph  2426  indicating (to the user) that the biometric authentication was successful. In some examples, glyph  2426  replaces one or more rotating rings  2424  within the biometric authentication interface. 
     In  FIG. 24I , subsequent to electronic device  2400  determining that the biometric authentication was successful, the electronic device indicates (to the user) that authorization has been provided to proceed with a payment transaction using the currently-selected payment account (e.g., payment account  2414 ), and thus that the payment transaction can be initiated. In some examples, electronic device  2400  displays a text indication  2428 A and/or a graphical indication  2428 B to indicate that the payment transaction can be initiated. In some examples, text indication  2428 A and/or graphical indication  2428 B replaces biometric authentication interface  2420  on pay user interface  2412 , as shown in  FIG. 24I . In some examples, graphical indication  2428 B replaces glyph  2426  within pay user interface  2412 . 
     In  FIG. 24J , while displaying pay user interface  2412  with payment account  2414  selected and authorized for use in a payment transaction, electronic device  2400  detects (e.g., via a wireless transmission radio of the device), a second device  2430  (e.g., a transaction terminal) different from the electronic device. In response to detecting the second device (e.g., a transaction terminal), electronic device  2400  transmits (e.g., via a wireless transmission radio of the device) payment credentials associated with payment account  2414  to the second device to complete the payment transaction. 
     In some examples, after successfully transmitting the payment credentials to second device  2430 , electronic device  2400  updates text indication  2428 A (e.g., to “Payment Completed”) and/or graphical indication  2428 B (e.g., to a check mark) within pay user interface  2412  to indicate (to the user) that the payment transaction has been successfully completed, as shown in  FIG. 24K . 
     In some examples, prior to proceeding with the payment transaction with a second device (e.g., a transaction terminal) using payment account  2414 , a different payment account can be selected for use in the transaction. In some examples, as shown in  FIG. 24L , electronic device  2400  displays within pay user interface  2412  (e.g., at a bottom region of the interface), one or more representations of payment accounts (e.g., payment accounts  2432 A- 2432 C) different from currently-selected payment account  2414 . In some examples, as shown in  FIG. 24L , electronic device  2400  receives user selection  2406  (e.g., a tap gesture) of a different payment account (e.g., payment account  2432 A) of the one or more payment accounts different from payment account  2414 . 
     In some examples, if the second device is a transaction terminal at a store, in order to authorize an in-store payment using biometric authentication (e.g., facial recognition authentication), the user must first confirm intent to pay by activating a hardware button (e.g., button  2404 , by double-clicking the Sleep/Wake button). In some examples, the user then authenticates using biometric authentication (e.g., facial recognition authentication) before placing the device near the second device (e.g., the transaction terminal). In some examples, if the user would like to select a different payment method after biometric authentication (e.g., facial recognition authentication), the device prompts the user to re-authenticate with the biometric authentication, but does not require that the user activate the hardware button (e.g., button  2404 ) (e.g., double-click the Sleep/Wake button again). 
     In some examples, upon user selection  2406  of payment account  2432 A, the representation of payment account  2432 A slides up within pay user interface  2412  and the representation of payment account  2414  slides down within pay user interface  2412 , as shown in  FIG. 24M . In some examples, the representation of payment account  2432 A slides up within pay user interface  2412  to the location previously occupied by the representation of payment account  2414  (thereby indicating to the user that payment account  2432 A is now selected for use in the payment transaction) and the representation of payment account  2414  slides down within pay user interface  2412  to join the one or more representations of payment accounts different from the currently-selected payment account, as shown in  FIG. 24N . Once the currently-selected payment account has been switched from payment account  2414  to payment account  2432 A, the device can proceed with the payment transaction (e.g., as described with reference to  FIG. 24J ) using payment account  2432 A to complete the transaction. 
     In some examples, the technique described with reference to  FIGS. 24B-24N  can be initiated (e.g., as is initiated by activation  2401  in accordance with prompt  2416 ) while electronic device  2400  is displaying, on display  2402 , an application  2434  (e.g., a messaging application) different from instruction user interface  2410 , as shown in  FIG. 24O . For example,  FIG. 24O  illustrates electronic device  2400  displaying, on display  2402 , an application  2434  (e.g., a messaging application). While displaying application  2434 , electronic device  2400  receives a user activation (e.g., double press  2405 ) of button  2404 . In response to receiving the user activation, the electronic device proceeds with the technique described with reference to  FIGS. 24B-24N  to obtain biometric authentication for proceeding with a payment transaction (e.g., with a second device different from the electronic device). 
     In some examples, the technique described with reference to  FIGS. 24B-24N  can be initiated (e.g., as is initiated by activation  2401  in accordance with prompt  2416  or by activation  2405  while application  2434  is displayed) while display  2402  of electronic device  2400  is in an off state, as shown in  FIG. 24P . While display  2402  is in an off state, electronic device  2400  receives a user activation (e.g., double press  2407 ) of button  2404 . In response to receiving the user activation, the electronic device proceeds with the technique described with reference to  FIGS. 24B-24N  to obtain biometric authentication for proceeding with a payment transaction (e.g., with a second device different from the electronic device). 
       FIG. 24Q  illustrates electronic device  2400  with display  2402  in an off state. While display  2402  is in the off state, the electronic device detects (e.g., via a wireless communication radio of the device) second device  2430  (e.g., a transaction terminal). In some examples, in response to detecting second device  2430  while display  2402  is in the off state, electronic device  2400  displays, on display  2402 , pay user interface  2412  and prompt  2416  (e.g., as illustrated in  FIG. 24B ) for proceeding with a payment transaction. 
     If electronic device  2400  determines that the biometric authentication is unsuccessful (e.g., the biometric data does not match a biometric template associated with the user), the device does not transition from the first state to the second state, and in some examples, the electronic device remains in the first state (e.g., authorization for proceeding with a payment transaction remains disabled). In some examples, the electronic device further indicates that the biometric authentication was unsuccessful, for instance, by displaying a simulation of a representation of the biometric feature in biometric authentication interface  2420 . As shown in  FIG. 24R , in some examples, biometric authentication interface  2420  includes a glyph  2436  indicating that the biometric authentication was unsuccessful. Glyph  2436  indicates, for instance, that the biometric feature was not recognized by the electronic device. In some examples, in addition to glyph  2436  within biometric authentication interface  2420 , electronic device  2400  generates a tactile output  2438  (e.g., a haptic feedback) that further indicates (to the user) that the biometric authentication was unsuccessful. 
     In some examples, glyph  2436  further moves (e.g., horizontally or vertically) within a region of biometric authentication interface  2420  to further indicate (to the user) that the biometric authentication was unsuccessful. For example, as shown in the transition from  FIG. 24R  to  FIG. 24S  to  FIG. 24T , glyph  2436  slides back and forth in a horizontal direction (e.g., repeating a left-to-right continuous sliding movement) for a predetermined period of time (e.g., 3 seconds). In some examples, the device continues to generate tactile output  2438  (e.g., a haptic feedback) during the duration of the movement of glyph  2436  within biometric authentication interface  2420 . In some examples, the tactile output  2438  is synchronized with movement of the glyph  2436 . 
     In some examples, as shown in  FIG. 24U , while displaying glyph  2436  within biometric authentication interface  2420  indicating to the user that the biometric authentication was unsuccessful, electronic device  2400  displays within pay user interface  2412  (e.g., below biometric authentication interface  2420 ) an alternative authentication affordance  2440  for providing alternative (e.g., passcode, password) authentication (e.g., in addition to or instead of biometric authentication) to proceed with the payment transaction. In some examples, while displaying alternative authentication affordance  2440  for providing alternative authentication, the electronic device detects user selection  2411  (e.g., a tap gesture) of the affordance, as shown in  FIG. 24V . 
     As shown in  FIG. 24W , in response to detecting the user selection of affordance  2440 , electronic device  2400  displays, on display  2402 , an alternative authentication interface  2442 . In some examples, electronic device  2400  performs biometric authentication during display of alternative authentication interface  2442 . In some examples, the electronic device obtains and processes biometric data to determine whether the obtained biometric data matches a biometric template associated with the user. As such, in some examples, alternative authentication interface  2442  includes a simulation of a representation of the biometric feature, such as a glyph  2444  (e.g., corresponding to glyph  2422 ), as shown in  FIG. 24W . In some examples, alternative authentication interface  2442  indicates that the biometric data is being processed by the electronic device, for instance, by displaying one or more rotating rings  2446  (e.g., corresponding to one or more rotating rings  2424 ), as shown in  FIG. 24X . In some examples, one or more rotating rings  2446  replaces glyph  2444  within the alternative authentication interface. 
     If electronic device  2400  determines that the biometric authentication is successful (e.g., the biometric data matches a biometric template associated with the user), the device transitions from a first state in which a function (e.g., authorization for transmitting payment credentials) is disabled to a second state in which the function is enabled. In some examples, successful biometric authentication enables the electronic device to transfer payment credentials (e.g., associated with payment account  2414 ) to, for example, a transaction terminal. In some examples, the electronic device further indicates that the biometric authentication was successful, for instance, by displaying a simulation of a representation of the biometric feature in alternative authentication interface  2442 . As shown in  FIG. 23Y , in some examples, alternative authentication interface  2442  includes a glyph  2448  (e.g., corresponding to glyph  2426 ) indicating (to the user) that the biometric authentication was successful. In some examples, glyph  2448  replaces one or more rotating rings  2446  within the alternative authentication interface. 
     In some examples, in addition or instead of biometric authentication, electronic device  2400  performs passcode authentication during display of alternative authentication interface  2442 . Accordingly, the electronic device receives and processes passcode data to determine whether the received passcode data matches an enrolled passcode associated with the user. As such, in some examples, alternative authentication interface  2442  includes an indication of the received passcode input, such as passcode indication  2450 , as shown in  FIG. 23Y . 
     In  FIG. 24Z , subsequent to electronic device  2400  determining that biometric authentication (and/or an alternative authentication, such as passcode authentication) was successful, the electronic device indicates (to the user) that authorization has been provided to proceed with a payment transaction using the currently-selected payment account (e.g., payment account  2414 ), and thus that the payment transaction can be initiated (e.g., with a transaction terminal). In some examples, electronic device  2400  displays a text indication  2452 A (e.g., corresponding to text indication  2428 A) and/or a graphical indication  2452 B (e.g., corresponding to graphical indication  2428 B) to indicate that the payment transaction can be initiated. 
       FIG. 24AA  illustrates electronic device  2400  displaying, on display, alternative authentication interface  2442  similar to that of  FIG. 24W . As in  FIG. 24W , electronic device  2400  performs biometric authentication during display of alternative authentication interface  2442 . Accordingly, the electronic device obtains and processes biometric data to determine whether the obtained biometric data matches a biometric template associated with the user. As such, alternative authentication interface  2442  includes glyph  2444  indicating to the user that biometric data has been (or is being) obtained. In  FIG. 24AB , as in  FIG. 24X , alternative authentication interface  2442  indicates that the biometric data is being processed by the electronic device, for instance, by displaying one or more rotating rings  2446 . 
     If electronic device  2400  determines that the biometric authentication is unsuccessful (e.g., the biometric data does not match a biometric template associated with the user), the electronic device forgoes transitioning from a first state in which a function (e.g., authorization for transmitting payment credentials) is disabled to a second state in which the function is enabled (thereby disallowing the device from proceeding with the payment transaction). In some examples, electronic device  2400  further indicates (to the user) that the biometric authentication was unsuccessful, for instance, by displaying a simulation of a representation of the biometric feature in alternative authentication interface  2442 . As shown in  FIG. 23AC , in some examples, alternative authentication interface  2442  includes a glyph  2454  (e.g., corresponding to glyph  2436 ) indicating (to the user) that the biometric authentication was unsuccessful. 
       FIG. 24AD  illustrates electronic device  2400  displaying, on the display  2402 , alternative authentication interface  2442  after the unsuccessful biometric authentication. The electronic device displays with an indication (e.g., via glyph  2454 ) that the biometric authentication was unsuccessful. In some examples, as shown in  FIG. 24AE , following an unsuccessful biometric authentication, electronic device  2400  receives one or more activations of button  2404  (e.g., a double press of button  2404 ) to re-start the biometric authentication process (e.g., as described with reference to  FIGS. 24B-24J ) while displaying alternative authentication interface  2442 . Thus, upon failing a biometric authentication and/or alternative authentication process, a user can re-attempt the process via one or more activations of button  2404 . In some examples, if the biometric authentication process is unsuccessfully attempted for a predetermined consecutive number of attempts or is unsuccessfully attempted for a predetermined consecutive number of attempts within a predetermined period of time, one or more activations of button  2404  (e.g., a double press of button  2404 ) no longer enables the re-start of the biometric authentication process (e.g., as described with reference to  FIGS. 24B-24J ). 
     In  FIG. 24AF , electronic device  2400  detects (e.g., via a wireless communication radio of the device), while displaying alternative authentication interface  2442 , second device  2430  (e.g., a transaction terminal). In some examples, in response to detecting second device  2430 , the electronic device while displaying the alternative authentication interface, electronic device  2400  displays the pay user interface and a prompt (e.g., corresponding to prompt  2416  as illustrated in  FIG. 24B ) for proceeding with a payment transaction. 
       FIG. 24AG  illustrates electronic device  2400  displaying, on display  2402 , pay user interface  2412  and authorized to initiate a transaction (e.g., after successfully being provided with biometric and/or alternative, such a passcode, authentication) using the currently-selected payment account (e.g., payment account  2414 ). In some examples, pay user interface  2412  includes a menu tab  2456  (e.g., at a bottom region of the interface, next to the bottom edge of the display), as shown in  FIG. 24AG . In some examples, electronic device detects a sliding gesture  2415  (e.g., in an upwards direction) of menu tab  2456 . For example, sliding gesture  2415  corresponds to a touch-and-slide (in the upwards direction) gesture of menu tab  2456 . 
     In some examples, sliding gesture  2415  on menu tab  2456  expands the menu tab (e.g., over pay user interface  2412 ), as shown in  FIG. 0.24AH . Once expanded, menu tab  2456  includes one or more application affordances (e.g., application affordances  2456 A- 2456 D) corresponding to applications installed on the device and accessible from the menu tab. For example, menu tab  2456  includes a first application affordance  2456 A corresponding to a messaging application, a second application affordance  2456 B corresponding to a voice call application, a third application affordance  2456 C corresponding to an email application, and a fourth application affordance  2456 D corresponding to a browsing application. In some examples, only first party applications (controlled only by the operating system of the device) can be included within menu tab  2456 . 
       FIG. 24AI  illustrates electronic device  2400  detecting sliding gesture  2415  while the gesture is sliding in a downwards direction on the display (and thus shrinking the expanded menu bar). As a result of the sliding gesture  2415  of menu bar  2456  in a downwards direction, the menu bar shrinks (or collapses back into) its original size and location (e.g., at the bottom of pay user interface  2412 ), as shown in  FIG. 24AJ . Once the menu bar has been fully collapsed, the pay user interface is again fully visible on the display. 
       FIG. 24AK  illustrates electronic device  2400  displaying, on display  2402 , a webpage  2458  of a browsing application. For example, webpage  2458  is a checkout page of an item  2460  that the user wishes to purchase and includes a purchase affordance  2462  for proceeding with purchasing the item. In some examples, as shown in  FIG. 24AK , the electronic device detects user activation  2417  of purchase affordance  2462 . 
     In some examples, upon detecting user activation of purchase affordance  2462 , electronic device  2400  displays, on display  2402 , a pay sheet interface  2464 , as shown in  FIG. 24AL . In some examples, pay sheet interface  2464  (partially) overlays the browsing application and includes biometric authentication interface  2420 . In some examples, as also shown in  FIG. 24AL , in addition to the pay sheet interface, the device further displays a prompt  2466  (e.g., corresponding to prompt  2416 ) indicating (to the user) to provide one or more activations (e.g., a double press of button  2404 ) to proceed with providing authorization for the purchase. 
     In some examples, pay sheet interface  2464  includes one or more details (e.g., payment account, shipping method, billing address, shipping address, contact information) related to the proposed transaction, as shown in  FIG. 24AL . In some examples, the one or more details include a selected payment account. In some examples, the user can change the selected payment account to a different payment account by selecting (a region within or an icon within) a detail region  2464 A corresponding to the selected payment account. In some examples, the one or more details include a selected shipping method. In some examples, the user can change the selected shipping method to a different shipping method by selecting (a region within or an icon within) a detail region  2464 B corresponding to the selected shipping method. In some examples, the one or more details include a selected address (e.g., billing address, shipping address). In some examples, the user can change the selected address to a different address by selecting (a region within or an icon within) a detail region  2464 C corresponding to the selected address. In some examples, the one or more details include a selected contact information (e.g., email, phone number). In some examples, the user can change the selected contact information to a different contact information by selecting (a region within or an icon within) a detail region  2464 D corresponding to the selected contact information. 
     In  FIG. 24AM , subsequent to displaying pay sheet interface  2464  and prompt  2466  over webpage  2458  of the browsing application, electronic device  2400  detects an input (e.g., double press of button  2404 ) corresponding to the request of prompt  2466 . In some examples, upon receiving the input (e.g., double press of button  2404 ) corresponding to the request of prompt  2466 , a glyph  2468  (e.g., corresponding to glyph  2422 ) is provided within biometric authentication interface  2420  displayed within pay sheet interface  2464 . Further in response to the input, one or more biometric sensors of electronic device  2400 , such as the one or more cameras or a facial recognition sensor (e.g., include among one or more biometric sensors  2403 ), are activated. 
     In some examples, once the one or more biometric sensors are activated, electronic device  2400  obtains (e.g., captures) biometric data corresponding to the biometric feature associated with the user. In some examples, the biometric feature captures the biometric data using one or more biometric sensors  2403  (and/or of the one or more cameras) of the electronic device. Optionally, a light-emitting device, such as an IR flood light or a structured light projector is used to assist in illuminating the biometric feature. In other examples, the electronic device receives the biometric data from another device. 
     In some examples, once electronic device  2400  has obtained the biometric data, the electronic device processes (e.g., analyzes) the biometric data to determine whether the biometric authentication is successful. In some examples, this determination includes determining whether the biometric data matches a biometric template associated with the user. The biometric template is, optionally, stored on electronic device  2400 . 
     In some examples, as illustrated in  FIG. 24AO , biometric authentication interface  2420  within pay sheet interface  2464  indicates that the biometric data is being processed by the electronic device, for instance, by displaying one or more rotating rings  2470  (e.g., corresponding to one or more rotating rings  2424 ) using the biometric authentication interface. In some examples, one or more rotating rings  2470  replaces glyph  2468  within the biometric authentication interface. 
     If electronic device  2400  determines that biometric authentication is successful (e.g., the biometric data matches a biometric template associated with the user), the electronic device transitions from a first state in which a function (e.g., authorizing transmission of payment credentials for use in a payment transaction) is disabled to a second state in which the function is enabled. As such, if the biometric authentication is successful, the device is in a state where payment credentials (e.g., associated with payment account  2472 ) are authorized to be transmitted (e.g., to a transaction terminal, to an external server) for use in a payment transaction (e.g., to make a purchase of item  2460 . In some examples, the electronic device further indicates that the biometric authentication was successful, for instance, by displaying a glyph  2474  (e.g., corresponding to glyph  2426 ) indicating (to the user) that the biometric authentication was successful, as shown in  FIG. 24AP . In some examples, glyph  2474  replaces one or more rotating rings  2470  within the biometric authentication interface. 
     In some examples, in response to the determination that the biometric authentication was successful, electronic device  2400  processes the payment transaction (e.g., transmits payment credentials to an external device, such as an external server and receives a response from the external device indicating that the credentials were successfully received). In some examples, as shown in  FIG. 24AQ , electronic device  2400  also displays a processing indication  2476  (e.g., with a similar or identical pattern to one or more rings  2470 ) within pay sheet interface  2464  indicating (to the user) that the payment transaction is being processed. In some examples, once the processing of the transaction is completed, electronic device  2400  replaces processing indication  2476  with a completed indication  2467  (e.g., which includes a checkmark to indicate completion), as shown in  FIG. 24AR , thereby indicating (to the user) that the payment transaction has been successfully completed (and that item  2460  has been successfully purchased. 
     In some examples, to make a payment within an application or on the web (e.g., webpage  2458 ), the electronic device requires that the user confirm the intent to pay by activating a hardware button (e.g., button  2404 ) (e.g., double-clicking the Sleep/Wake button), then authenticate using biometric authentication (e.g., facial recognition authentication) to authorize the payment. In some examples, if the payment transaction is not completed within a predetermined time threshold (e.g., 30 seconds) of activating the hardware button (e.g.,  2404 ) (e.g., double-clicking the Sleep/Wake button), the device requires that the user reconfirm intent to pay by activating the hardware button (e.g., button  2404 ) (e.g., double-clicking the Sleep/Wake button) again. 
       FIG. 24AS  illustrates electronic device  2480  (e.g., a laptop computer) displaying, on display  2482 , a webpage  2484  (e.g., similar to webpage  2458 ) of a browsing application. For example, webpage  2484  is a checkout page of an item  2486  that the user wishes to purchase. In some examples, webpage  2484  of the browsing application includes a purchase affordance  2488  for providing authorization to proceed with purchasing the item using a device different from electronic device  2480  (e.g., using electronic device  2400 ). 
     In some examples, user activation of purchase affordance  2488  on electronic device  2480  causes electronic device  2400  to display a remote pay user interface  2490 , as shown in  FIG. 24AT . In some examples, remote pay user interface  2490  includes a (graphical) indication  2492  of the device (e.g., electronic device  2480 ) that is requesting the remote authentication for proceeding with a payment transaction, an indication  2494  of the payment account currently selected for user in the payment transaction, and a prompt  2496  (e.g., corresponding to prompt  2416 ) requesting that the user provide one or more activations of button  2404  (e.g., a double press) to proceed with providing authentication (e.g., biometric authentication) for the payment transaction. In some examples, as also shown in  FIG. 24AT , prompt  2496  is emphasized relative to one or more other displayed objects (e.g., relative to indication  2492  of electronic device  2480 ). Emphasizing the prompt in this manner includes, for instance, darkening, blurring, and/or otherwise obfuscating one or more portions of remote pay user interface  2490 . 
     In some examples, indication  2494  of the payment account currently selected for use in the payment transaction includes an affordance  2494 A. In some examples, as shown in FIG.  24 AU, electronic device  2400  detects user activation  2421  (e.g., a tap gesture) of affordance  2494 A. In some examples, in response to detecting the user selection of affordance  2494 A, electronic device  2400  displays, within remote pay user interface  2490 , representations of one or more payment accounts (e.g., payment account  2494 , payment account  2498 ) provisioned on the device (and thus available for use in a payment transaction), as shown in  FIG. 24AV . In some examples, as also shown in  FIG. 24AV , the representation of the currently-selected payment account also includes an indication  2494 B (e.g., a checkmark) indicating (to the user) that it corresponds to the currently selected account. 
     In  FIG. 24AW , while displaying within remote pay user interface  2490  the representations of payment accounts (e.g., payment account  2494 , payment account  2498 ) provisioned on the electronic device, electronic device  2400  detects user selection  2423  of a payment account (e.g., payment account  2498 ) that is different from the currently-selected payment account (e.g., payment account  2494 ). In response to detecting user selection  2423  of payment account  2498 , electronic device  2400  removes the representations of available payment accounts from remote pay user interface  2490  and displays payment account  2498  (instead of payment account  2494 ) as the payment account currently selected for use in a payment transaction, as shown in  FIG. 24AX . 
     As also shown in  FIG. 24AX , after replacing payment account  2494  with payment account  2498 , electronic device  2400  detects one or more activations  2425  (e.g., a double press) of button  2404  that corresponds to the request of prompt  2496 . In  FIG. 24AY , in response to detecting one or more activations  2425  of button  2404 , electronic device  2400  displays, within remote pay user interface  2490 , biometric authentication interface  2420 . In some examples, the electronic device further displays a glyph  2499  (e.g., corresponding to glyph  2422 ) within biometric authentication interface  2420  displayed within remote pay user interface  2490 . Further in response to the input, one or more biometric sensors of electronic device  2400 , such as the one or more cameras or a facial recognition sensor (e.g., include among one or more biometric sensors  2403 ), are activated. 
     In some examples, once the one or more biometric sensors are activated, electronic device  2400  obtains (e.g., captures) biometric data corresponding to the biometric feature associated with the user. In some examples, the biometric feature captures the biometric data using one or more biometric sensors  2403  (and/or of the one or more cameras) of the electronic device. Optionally, a light-emitting device, such as an IR flood light or a structured light projector is used to assist in illuminating the biometric feature. In other examples, the electronic device receives the biometric data from another device. 
     In some examples, once electronic device  2400  has obtained the biometric data, the electronic device processes (e.g., analyzes) the biometric data to determine whether the biometric authentication is successful. In some examples, this determination includes determining whether the biometric data matches a biometric template associated with the user. The biometric template is, optionally, stored on electronic device  2400 . 
     In some examples, as illustrated in  FIG. 24AZ , biometric authentication interface  2420  within remote pay user interface  2490  indicates that the biometric data is being processed by the electronic device, for instance, by displaying one or more rotating rings  2497  (e.g., corresponding to one or more rotating rings  2424 ) using the biometric authentication interface. In some examples, one or more rotating rings  2497  replaces glyph  2499  within the biometric authentication interface. 
     If electronic device  2400  determines that biometric authentication is successful (e.g., the biometric data matches a biometric template associated with the user), the electronic device transitions from a first state in which a function (e.g., authorizing transmission of payment credentials for use in a payment transaction) is disabled to a second state in which the function is enabled. As such, if the biometric authentication is successful, the device is in a state where payment credentials (e.g., associated with payment account  2498 ) are authorized to be transmitted (e.g., to a transaction terminal, to an external server) for use in a payment transaction (e.g., to make a purchase of item  2486 . In some examples, the electronic device further indicates that the biometric authentication was successful, for instance, by displaying a glyph  2495  (e.g., corresponding to glyph  2426 ) indicating (to the user) that the biometric authentication was successful, as shown in  FIG. 24BA . In some examples, glyph  2495  replaces one or more rotating rings  2497  within biometric authentication interface  2420  of remote pay user interface  2490 . 
     In some examples, in response to the determination that the biometric authentication was successful, electronic device  2400  processes the payment transaction (e.g., transmits payment credentials to an external device, such as an external server and receives a response from the external device indicating that the credentials were successfully received). In some examples, as shown in  FIG. 24BB , electronic device  2400  also displays a processing indication  2493  (e.g., with a similar or identical pattern to one or more rings  2497 ) within remote pay user interface  2490  indicating (to the user) that the payment transaction is being processed. In some examples, once the processing of the transaction is completed, electronic device  2400  replaces processing indication  2493  with a completed indication  2491  (e.g., which includes a checkmark to indicate completion), as shown in  FIG. 24BC , thereby indicating (to the user) that the payment transaction has been successfully completed (and that item  2486  has been successfully purchased. 
       FIGS. 25A-25C  are a flow diagram illustrating a method for performing biometric authentication using an electronic device in accordance with some examples. Method  2500  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1900 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric feature by the one or more biometric sensors. Some operations in method  2000  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  2500  provides an intuitive way for managing biometric authentication. The method reduces the cognitive burden on a user for managing biometric authentication, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to manage biometric authentication faster and more efficiently conserves power and increases the time between battery charges. 
     In some examples, the electronic device (e.g.,  2300 ,  2400 ) receives ( 2502 ), from a second device, a request to proceed with an action, where the request includes information associated with one or more options selected at the second device. In some examples, the electronic device receives a request to proceed with a transaction and further receives information from the second device regarding details of the transaction. In some examples, the action involves a transaction. In some examples, before receiving a user input corresponding to a request to participate in the transaction, the electronic device receives, from the second device, input corresponding to a transaction, where the input includes one or more details of the transaction, and displays one or more transaction details associated with the transaction along with a request for authorization to proceed with the transaction. 
     The electronic device (e.g.,  2300 ,  2400 ), while the electronic device is in a first state in which a respective function of the device is disabled, detects ( 2508 ) one or more activations of the button (e.g.,  2304 ,  2404 ) (e.g., double press of a button such as a hardware button or mechanical button, double press of button  2304  or button  2404 ). In some examples, the respective function is associated with a financial transaction, such as a payment for a good or service. In some examples, in instances in which the function is disabled, the device cannot participate in the transaction. 
     In some examples, the respective function of the electronic device (e.g.,  2300 ,  2400 ) is participation in a transaction ( 2510 ). In some examples, participation in the transaction includes transmission of secured data from the electronic device. In some examples, the secured data is financial data. In some examples, the transaction additionally or alternatively includes the transmission of unsecured data. In some examples, information enabling the device to participate in the transaction is securely stored in a secure element (e.g., a physically and/or logically segregated memory that stores credentials in such a way that they are prevented from being maliciously accessed). In some examples, the electronic device is not enabled to participate in the transaction (e.g., a financial transaction, such as a payment for a good or service) when in the first state. In some examples, when the device is in the first state, the information enabling the device to participate in the transaction is not accessible at the device outside of the secure element (e.g., payment credentials are not available for use in a wireless payment transaction). 
     In some examples, the respective function of the electronic device (e.g.,  2300 ,  2400 ) is a function to provide information associated with an action via a short range communication radio of the electronic device ( 2512 ). In some examples, the electronic device is in the first state while in an inactive state in which the display (e.g.,  2302 ,  2402 ), biometric sensor(s) (e.g.,  2303 ,  2403 ), and/or one or more other components of the device is inactive. In some examples, because the respective function of the device is a function to provide information (e.g., payment information) associated with an action (e.g., a transaction) via a short range communication radio (e.g., NFC transmitter) of the device, the electronic device is not configured to participate in transactions when in the first state. For example, the device does not respond to requests for payment information with the payment information until authorization to provide the payment information is provided by the user, such as a double click of a hardware button (e.g.,  2304 ,  2404 ) received in conjunction with biometric or passcode/password authentication. 
     In some examples, the one or more activations of the button (e.g.,  2304 ,  2404 ) occur at least partly while a display of the electronic device (e.g.,  2300 ,  2400 ) is off or displaying a user interface that is not related to payment ( 2514 ) (e.g., a lock screen user interface, a cover sheet user interface that includes a plurality of recent notifications, a home screen user interface that includes application icons for a plurality of different applications and optionally one or more widgets, or an application user interface for an application that is not a payment application such as an email application, a phone application, a messages application, or a camera application). 
     In some examples, while the display of the electronic device (e.g.,  2300 ,  2400 ) is off or displaying a user interface that is not related to payment, the electronic device is not configured to transmit payment information to a payment terminal (e.g.,  2430 ), in response to a request for payment information (e.g., to protect the payment information from being inadvertently provided in situations where the user does not intend to provide the payment information). In some examples, in at least some circumstances when the display of the device is off or displaying a user interface that is not related to payment, the electronic device listens for requests for payment information and responds to at least some requests for payment information by displaying a payment user interface (e.g., a virtual wallet) that informs the user that payment information has been requested and prompts the user to provide authorization to provide the payment information. 
     In some examples, the one or more activations of the (hardware) button include a double press of the button ( 2516 ) (e.g., a first and second press of the button within a predetermined period of time). In some examples, the hardware button (e.g.,  2304 ,  2404 ) is located on a side of the electronic device (e.g.,  2300 ,  2400 ). In some examples, the hardware button is a mechanical button. In some examples, the activation of the button without a second activation of the button within the predetermined time period performs a different function (e.g., turning on or off a display of the device). In some examples, a different activation of the button (e.g., a long press of the button for a different time period) causes a different function (e.g., entering a user interface for powering off the device or invoking a virtual assistant) to occur. 
     In some examples, the one or more activations of the (hardware) button (e.g.,  2304 ,  2404 ) are detected while a first application is active on the electronic device ( 2518 ). In some examples, detecting the one or more activations of the button occurs while displaying the tutorial interface (e.g.,  2410 ) ( 2520 ). In some examples, the electronic device (e.g.,  2300 ,  2400 ) does not display the tutorial interface, but rather displays the biometric authentication interface (e.g.,  2322 ,  2420 ) and performs biometric authentication. Performing biometric authentication (e.g., as opposed to a different type of authentication, such as password authentication) allows the user to more quickly and easily (e.g., with no inputs and within a shorter period of time) provide authentication for performing a particular operation (e.g., a transaction) using the device. Reducing the number of inputs needed to perform an operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the button (e.g.,  2304 ,  2404 ) has a fixed location relative to a display of the electronic device (e.g.,  2300 ,  2400 ) (e.g., the button is not purely a software button). In some examples, the button is a hardware button, such as a mechanical button or a solid state button. In some examples, the button is a switch or any other type of toggle. In some examples, the button has a fixed position relative to the electronic device, and in particular, relative to the display of the electronic device such that the electronic device can display prompts based on a position of the button. 
     In some examples, the button (e.g.,  2304 ,  2404 ) is a mechanical button (e.g., a hardware button, such as a push button). In some examples, the button is not a software button, such as a button on a touchscreen of the electronic device (e.g.,  2300 ,  2400 ). In some examples, the button is a solid-state button. In some examples, the button is a solid-state button that operates according to capacitive and/or resistive touch, and/or is responsive to changes in the intensity of input without having a mechanical switch that is depressed to activate the button and instead monitors whether an intensity of the input is above an intensity threshold that corresponds to activation of the solid-state button. 
     In some examples, prior to detecting ( 2508 ) the one or more activations of the button (e.g.,  2304 ,  2404 ), the electronic device (e.g.,  2300 ,  2400 ) outputs ( 2504 ) (e.g., by displaying on the display) a prompt (e.g.,  2318 ,  2416 ) requesting that one or more activations of the button be provided. In some examples, the electronic device prompts the user by displaying “Double Click for Pay”. In some examples, the prompt is displayed on the display (e.g.,  2302 ,  2404 ) of the electronic device. In some examples, the prompt is displayed adjacent to the button. In some examples, the prompt is an auditory and/or tactile prompt. In some examples, the prompt is displayed when the device is displaying a transaction user interface but without receiving any indication that a transaction terminal is nearby and is requesting transaction credentials (e.g., the prompt to provide the one or more activations of the button are displayed before the device as been placed in an NFC field of an NFC reader that is requesting payment information). In some examples, prior to outputting the prompt, the electronic device displays a tutorial interface including an affordance. 
     In some examples, outputting the prompt (e.g.,  2318 ,  2416 ) occurs in response to selection of the affordance. In some examples, the tutorial interface (e.g.,  2410 ) is displayed the first time a user attempts to implement the respective function without providing the one more activations of the button). In some examples, the tutorial interface includes an animation at a location that is based on a location of the button (e.g.,  2304 ,  2404 ) on the device (e.g., the animation includes movement of a user interface object in a direction in which the button can be pushed at a location adjacent to or proximate to the button on the device). 
     In some examples, outputting the prompt (e.g.,  2318 ,  2416 ) to a user to provide the one or more activations of the button includes emphasizing the prompt relative to one or more elements displayed on the display of the electronic device (e.g.,  2300 ,  2400 ) ( 2506 ). In some examples, emphasizing the prompt includes blurring, dimming, and/or ceasing to display at least a portion of the display of the electronic device. In some examples, emphasizing the prompt includes brightening the prompt, flashing the prompt, or otherwise drawing attention to the prompt. In some examples, emphasizing the prompt relative to the one or more elements displayed on the display of the electronic device includes blurring the one or more elements. In some examples, all elements displayed on the display (e.g.,  2302 ,  2402 ) (except for the prompt) are blurred. In some examples, only elements adjacent to the prompt are blurred. In some examples, emphasizing the prompt relative to the one or more elements displayed on the display of the electronic device includes dimming display of the one or more elements. In some examples, all elements displayed on the display (except for the prompt) are dimmed. In some examples, only elements adjacent to the prompt are dimmed. Dimming in this manner optionally includes decreasing brightness and/or darkening displayed colors. 
     In some examples, outputting the prompt (e.g.,  2318 ,  2416 ) occurs in response to detecting an external signal of a predetermined type. In some examples, the electronic device (e.g.,  2300 ,  2400 ) detects a signal, such as an NFC field from an NFC reader such as a payment terminal (e.g.,  2430 ), and prompts the user to provide input to initiate a biometric authentication process to authorize the device to make payment credentials available for transmission to the NFC reader. 
     In some examples, outputting the prompt (e.g.,  2318 ,  2416 ) includes displaying an educational interface including a prompting element adjacent to the button. In some examples, the electronic device (e.g.,  2300 ,  2400 ) prompts the user to provide the one or more activations of the button (e.g.,  2304 ,  2404 ) by way of an interface in which the prompt is displayed near the location of the button and/or indicates a location of the button. In some examples, the educational interface is displayed in instances in which the user has attempted to implement the respective function of the electronic device, but has not provided the one or more activations required to initiate biometric authentication such that the electronic device is enabled to implement the respective function. 
     In some examples, the electronic device (e.g.,  2300 ,  2400 ) displays, on the display, the prompt to provide the one or more activations of the button (e.g.,  2304 ,  2404 ) at a first position in the biometric authentication interface (e.g.,  2322 ,  2420 ). Outputting a prompt requesting that one or more activations of the button be provided provides the user with feedback about the current state of the device and provides visual feedback to the user indicating what steps the user must take in order to proceed with a particular function using the device. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device (e.g.,  2300 ,  2400 ) detects activation (e.g., selection) of an affordance of a first application (e.g., activation of an affordance of an application requesting a transaction for a good or service). In some examples, the first application is a communication application. In some examples, the device displays details of a transaction and one or more of the affordance for initiating the transaction and prompt for triggering biometric authentication. In some examples, the details of the transaction optionally are modified prior to activation of the affordance or prior to detection of a biometric feature after biometric authentication has been triggered by way of user input (e.g., a double press). 
     In some examples, in response to detecting ( 2522 ) the activation of the affordance of the first application, the electronic device (e.g.,  2300 ,  2400 ) provides (e.g., transfers) information associated with an action from the first application to a second application. In some examples, the action from the first application to the second application involves a transaction. In some examples, before receiving a user input corresponding to a request to participate in the transaction, the electronic device detects activation of an affordance of a first application, in response to detecting the activation of the affordance of the first application, provides information about a transaction from the first application to a second application, and proceeds with the transaction using the second application. 
     In some examples, the electronic device also concurrently displays, on the display (e.g.,  2302 ,  2402 ), at least a portion of the information associated with the action at a first location (e.g., in a payment user interface region that is separate from the first application and includes transaction information that is not shared with the first application such as a credit card number, billing address) and a second prompt to provide the one or more activations of the button at a second location, where the second location is closer to the button than the first location. 
     In some examples, prior to receiving the activation of the button (e.g.,  2304 ,  2404 ), details of a transaction are confined to a particular portion of the display such that the prompt to provide the activation of the button can be displayed proximate to the button. Confining the details of the transaction to a particular portion of the display such that the prompt can be displayed proximate to the relevant button provides the user with visual feedback allowing the user to more quickly and easily follow the request of the prompt. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the details are restricted to a particular height of the display. In some examples, if there is more information than can be displayed in the available region below the second prompt, the information associated with the action is displayed in a scrollable region that scrolls in response to user inputs to display additional information that was hidden (e.g., off of the screen) before the scrollable region scrolled. In some examples, providing information about the transaction from the first application to the second application includes providing information that can be displayed in the available region and the additional information that was hidden. 
     In some examples, after displaying the prompt (e.g.,  2318 ,  2416 ), the electronic device (e.g.,  2300 ,  2400 ) moves the representation of the user credential from a second position on the display (e.g.,  2302 ,  2402 ) to the first position on the display. In some examples, the representation of the user credential is moved such that the user credential covers the prompt to press (e.g., a double click) the button (e.g.,  2304 ,  2404 ) and/or reveals a biometric authentication glyph (e.g.,  2324 ,  2422 ). In some examples, moving the representation of the user credential from a second position to the first position includes displaying the biometric authentication glyph at a portion of the display that was occupied by the user credential when the user credential was displayed at the second position. 
     In response to detecting ( 2522 ) the one or more activations of the button, the electronic device (e.g.,  2300 ,  2400 ) captures ( 2524 ) with the one or more biometric sensors (e.g.,  2303 ,  2403 ) that are separate from the button (e.g.,  2304 ,  2404 ), biometric data. In some examples, in response to a double press of the hardware button, the device receives biometric data, such as data for a face of the user. In some examples, the one or more biometric sensors include a facial recognition sensor and the biometric data corresponds to at least a portion of a face. 
     In some examples, capturing biometric data includes capturing the biometric data using the camera. In some examples, the biometric data is captured using a camera and/or a facial recognition sensor (e.g.,  2303 ,  2403 ). In some examples, the camera is used to ensure that a user is looking at the device and the facial recognition sensor is used to authenticate a face of the user. 
     In some examples, capturing, with the one or more biometric sensors, biometric data includes activating the one or more biometric sensors (e.g.,  2303 ,  2403 ) for a second predetermined period of time. For example, in response to the press of the button (e.g.,  2304 ,  2404 ), the electronic device (e.g.,  2300 ,  2400 ) activates one or more biometric sensors (e.g.,  2303 ,  2403 ) (e.g., transitions the biometric sensors from an inactive state to an active state), such as a facial recognition sensor or a camera, and uses the activated one or more biometric sensors to capture the biometric data. In some examples, the activated one or more biometric sensors are activated for a period of time, and if biometric data is not captured during the period of time, the biometric authentication process fails. In some examples, the second predetermined period of time begins when the one or more activations of the button is detected. In some examples, the period of time is initiated when the button is pressed. In some examples, capturing biometric data in this manner includes illuminating the biometric feature and capturing data corresponding to the illumination. In some examples, the biometric feature is illuminated using an IR flood light or a structured light projector. 
     In some examples, in response to detecting ( 2522 ) the one or more activations of the button, the electronic device (e.g.,  2300 ,  2400 ) also displays ( 2526 ) a biometric authentication interface (e.g.,  2322 ,  2420 ) including a representation of a user credential that is restricted from being used without proper biometric authentication. In some examples, the biometric authentication interface includes an authentication glyph (e.g.,  2324 ,  2422 ) and/or one or more representations of user credentials (e.g., an image representing data that will be used by function of the electronic device, such as an image of a credit card, image of a bank account, image of business card). Providing an authentication glyph provides the user with easily visible and recognizable visual feedback about the current state or progress of the authentication process. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, the function uses the represented data to perform a transaction. In some examples, the biometric authentication is performed for a particular credential and the credential is highlighted relative to the other credentials. In some examples, the biometric authentication interface (e.g.,  2322 ,  2420 ) includes an animation (e.g., card carousel). 
     In accordance with a determination that the biometric data satisfies biometric authentication criteria (e.g., the biometric criteria matches a biometric template stored on the device), the electronic device (e.g.,  2300 ,  2400 ) transitions ( 2528 ) to a second state in which the respective function of the device is enabled. In some examples, in instances in which the device is enabled, the device can participate in the transaction. In some examples, the electronic device determines whether the biometric data satisfies the biometric authentication criteria. Limiting the device&#39;s ability to participate in the transaction to instances in which the device is enabled (to participate in the transaction) provides the user with more control of the device by helping the user to avoid unintentionally executing the transaction and simultaneously providing for enhanced device security. Providing additional control of the device without cluttering the UI with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device (e.g.,  2300 ,  2400 ) is enabled to participate in the transaction when in the second state. In some examples, when the device is in the second state the information enabling the device to participate in the transaction is temporarily made accessible at the device outside of the secure element by the secure element (e.g., payment credentials are available for use in a wireless payment transaction). 
     In some examples, after transitioning to the second state, the electronic device (e.g.,  2300 ,  2400 ) maintains ( 2530 ) the device in the second state for a first predetermined period of time (e.g., 60 seconds). In some examples, the function of the electronic device is enabled even on a change in user credentials (e.g., as a result of a card switch). In some examples, the first predetermined period of time begins when the one or more activations of the button is detected (e.g., when the button is pressed). In some examples, after transitioning to the second state, the electronic device, after the first predetermined period of time has elapsed, transitions ( 2532 ) from the second state to the first state. In some examples, after transitioning to the second state, the electronic device performs ( 2534 ), using the respective function of the electronic device, the action based on the information (e.g., transmitting credentials to a remote server for processing a transaction). In some examples, the electronic device proceeds with the transaction, using credentials provided in the request. In some examples, the credentials are provided to a remote server for processing the transaction. In some examples, the electronic device causes display, at the other device, of an indication indicating whether the authentication was successful. In some examples, the electronic device causes display, at the another device (e.g., the other device or the second device), of an indication indicating whether the transaction was successful. In some examples, the prompt is outputted while details of the transaction are displayed. 
     In some examples, while the device is in the second state, the electronic device (e.g.,  2300 ,  2400 ) detects ( 2536 ) a user input corresponding to a request to exit the first application. In some examples, in response to detecting the user input corresponding to a request to exit the first application, the electronic device exits ( 2538 ) the first application and transitions to the first state. In some examples, when the device is enabled to participate in the transaction, exiting the application in which the input that was received that caused the device to be enabled to participate in the transaction causes the device to cease to be enabled to participate in the transaction. In some examples, when the device has been authorized to provide payment credentials for a payment transaction in a wallet application and the device switches from the wallet application to a different application the device disables the ability to provide the payment credentials until providing payment credentials is reauthorized by the user (e.g., with biometric authentication). Thus, unintended transmission of payment information by disabling transmission of payment information when the device is not displaying a user interface that indicates that the device is configures to provide payment credentials is avoided. 
     In accordance with a determination that the biometric data does not satisfy the biometric authentication criteria (e.g., the biometric data does not match a biometric template stored on the device), the electronic device (e.g.,  2300 ,  2400 ) maintains ( 2540 ) the first state and displays ( 2540 ), on the display, an indication that biometric authentication has failed. Maintaining the first state (e.g., a state in which the device is not authorized to proceed with a transaction) when the authentication has failed provides the user with enhanced control and security of the device. Providing additional control and enhanced security of the device without cluttering the UI with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device (e.g.,  2300 ,  2400 ) also displays ( 2542 ) an alternative authentication affordance (e.g.,  2334 ,  2440 ). In some examples, the alternative authentication affordance is an affordance, which when selected, causes the electronic device to display an interface (e.g.,  2336 ,  2442 ) in which a user can provide an alternative form of authentication (e.g., a non-biometric form of authentication), such as a password, passcode, or pattern input. In some examples, successful authentication, via alternative authentication, causes the electronic device to transition to the second state. In some examples, a first failure causes display of a “try again” affordance and a second failure causes display of an alternative authentication affordance (e.g.,  2336 ,  2442 ) such as a “passcode” affordance. In some examples, the electronic device receives a user input, such as a double press of the button. In some examples, if the threshold number of biometric authentication attempts has been reached, the electronic device displays an affordance to enter a passcode (or password) and optionally, an indication that biometric authentication is not available and/or the threshold number has been reached (e.g., “Passcode required to enable FaceID”). 
     In some examples, after determining that the biometric data does not satisfy the biometric authentication criteria (e.g., while displaying the alternative authentication interface or the alternative authentication affordance), the electronic device (e.g.,  2300 ,  2400 ) detects ( 2544 ) selection of the alternative authentication affordance (e.g.,  2334 ,  2440 ). In some examples, in response to detecting selection of the alternative authentication affordance, the electronic device (e.g.,  2300 ,  2400 ) displays ( 2546 ), on the display, an alternative authentication interface (e.g.,  2336 ,  2442 ), such as a password or passcode interface, in response to selection of the affordance. 
     In some examples, the electronic device (e.g.,  2300 ,  2400 ) also captures ( 2548 ), with the one or more biometric sensors (e.g.,  2303 ,  2403 ), second biometric data. In some examples, in accordance with a determination that the second biometric data satisfies the biometric authentication criteria, the electronic device transitions ( 2550 ) to the second state. In some examples, in response to selection of the affordance, the electronic device performs a second iteration of biometric authentication. 
     In some examples, the biometric authentication is performed during display of, or transition to, the alternative authentication interface (e.g.,  2336 ,  2442 ). In some examples, the alternative authentication interface includes display of the biometric authentication glyph sequence such that the user is informed that biometric authentication is taking place. In some examples, successful biometric authentication bypasses the need for alternative authentication. As a result, the electronic device (e.g.,  2300 ,  2400 ) ceases display of the alternative authentication interface (e.g.,  2336 ,  2442 ) and proceeds as if the user had successfully authenticated on the first try. 
     In some examples, in accordance with a determination that the second biometric data does not satisfy the biometric authentication criteria, the electronic device (e.g.,  2300 ,  2400 ) maintains ( 2552 ) the first state and displays the alternative authentication interface (e.g.,  2336 ,  2442 ) on the display (e.g.,  2302 ,  2402 ). In some examples, on failure, display of the alternative authentication interface is maintained such that the user optionally provides the alternative authentication. Maintaining display of the alternative authentication interface (upon failure) such that the user can provide the alternative authentication provides the user with more control of the device by providing the user with a plurality of different ways to provide authentication (for a particular operation to be performed by the device. Providing additional control of the device without cluttering the UI with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device (e.g.,  2300 ,  2400 ) detects ( 2554 ) a respective user input that corresponds to a request to retry biometric authentication. In some examples, the electronic device detects a user input, such as a button press or movement of the electronic device (e.g., raise and/or lower of the device) or selection of the alternative authentication affordance (e.g.,  2334 ,  2440 ). In some examples, the user input that corresponds to the request to retry biometric authentication includes one or more activations of the button. In some examples, the user input includes the one or activations of the button used to initiate the first iteration of biometric authentication. In some examples, the user input that corresponds to the request to retry biometric authentication includes movement of the electronic device. In some examples, the user input of the predetermined type is an input that is different from activation of the button. In some examples, the user input of the predetermined type is a raising and/or lowering of the electronic device (e.g., the electronic device is lowered near another electronic device, such as an NFC-compatible device, and raised back to an eye level of the user. 
     In some examples, in response to detecting the user input that corresponds to the request to retry biometric authentication, the electronic device (e.g.,  2300 ,  2400 ) captures ( 2556 ), with the one or more biometric sensors, third biometric data. In some examples, in response to the user input, the device performs an additional iteration of biometric authentication. In some examples, in accordance with a determination that the third biometric data satisfies the biometric authentication criteria, the electronic device transitions ( 2558 ) to the second state in which the respective function of the device is enabled. In some examples, in accordance with a determination that the third biometric data does not satisfy the biometric authentication criteria, the electronic device maintains ( 2560 ) the first state (and, optionally, displays, on the display, an indication that biometric authentication has failed). 
     In some examples, the electronic device (e.g.,  2300 ,  2400 ) detects another one or more activations of the button (e.g.,  2304 ,  2404 ). In some examples, in accordance with a determination that biometric capture criteria is met, the electronic device captures, with the one or more biometric sensors (e.g.,  2303 ,  2403 ) that are separate from the button (e.g.,  2304 ,  2404 ), second biometric data. In some examples, in accordance with a determination that biometric capture criteria is not met, the electronic device forgoes capturing second biometric data. In some examples, the number of biometric authentication attempts is limited to a predetermined number (e.g., 5). In some examples, this number is reset in response to successful authentication. In some examples, this number is reset after a set amount of time. 
     Note that details of the processes described above with respect to method  1200  (e.g.,  FIGS. 25A-25C  are also applicable in an analogous manner to the methods described herein. For example, method  2500  optionally includes one or more of the characteristics of the various methods described herein with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  1800 ,  2000 ,  2200 , and  2700 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to  FIGS. 24F-G  For another example, one or more interstitial interfaces as described in methods  2000  and  2700  optionally are displayed in response to receipt of an input prior to completion of a biometric authentication process. For brevity, these details are not repeated herein. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 25A-25C  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, detecting operation  2508 , transitioning operation  2528 , and maintaining operation  2540 , are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 26A-26AS  illustrate exemplary user interfaces for biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary example of the user interfaces illustrated in  FIGS. 26A-26AS  are used to illustrate the processes described below, including the processes in  FIGS. 27A-27E . 
       FIG. 26A  illustrates an electronic device  2600  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary example illustrated in  FIGS. 26A-26AS , electronic device  1900  is a smartphone. In other examples, electronic device  1500  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  1900  has a display  2602 , one or more input devices (e.g., touchscreen of display  2602 , a button  2604 , a mic (not displayed)), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the electronic device includes one or more biometric sensors (e.g., biometric sensor  2603 ) which, optionally, include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the one or more biometric sensors  2603  are the one or more biometric sensors  703 . In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 26A , the electronic device, while in an unlocked state, displays an unlocked interface  2606 . The unlocked interface  2606  includes a notification affordance  2608  and an unlocked state indicator  2610 . In some examples, because the electronic device  2600  is in an unlocked state, the notification affordance  2608  includes an indication of secured content associated with the notification affordance  2608 . For example, as shown, the notification affordance is associated with a messaging application and includes at least a portion of a message received by the electronic device. 
     With reference to  FIGS. 26B-D , while displaying the unlocked interface  2606 , the electronic device  2100  detects a user input  2612  ( FIG. 26B ), for instance, near an edge of the display  2602 . The user input  2612  is a swipe gesture that, in some examples, is a request to access a home screen interface of the electronic device  2600 , and in response to the swipe input  2612 , the electronic device displays (e.g., replaces display of the unlocked interface  2606  with) the home screen interface  2614  of  FIG. 26D . In some examples, displaying the home screen interface  2129  includes sliding the unlocked interface  2606  in an upward direction to display (e.g., reveal) the home screen interface  2614 , as analogously described with reference to  FIGS. 19P-R . 
     In  FIG. 26E , the electronic device, while in an unlocked state, displays an unlocked interface  2606 . The unlocked interface  2606  includes a notification affordance  2608  and an unlocked state indicator  2610 . In some examples, because the electronic device  2600  is in an unlocked state, the notification affordance  2608  includes an indication of secured content associated with the notification affordance  2608 . For example, as shown, the notification affordance is associated with a messaging application and includes at least a portion of a message received by the electronic device. 
     While displaying the unlocked interface  2606 , the electronic device detects an activation of the notification affordance  2608 . The activation of the notification affordance  2608  is a tap gesture  2615  in some examples. In response to activation of the notification affordance  2608 , the electronic device displays (e.g., replaces display of the unlocked interface  2606  with) the messaging application interface  2616  of  FIG. 26G . With reference to  FIGS. 21F-G , in some examples, displaying the messaging application interface  2616  includes sliding the unlocked interface  2606  in an upward direction to display (e.g., reveal) the messaging application interface  2616 , as analogously described with reference to  FIGS. 19P-R . 
     In  FIG. 26H , the electronic device, while in a locked state, displays a locked interface  2620 . The locked interface  2620  includes a notification affordance  2622  and a locked state indicator  2624 . In some examples, because the electronic device  2600  is in a locked state, the notification affordance  2622  does not include an indication of secured content associated with the notification affordance  2622 . 
     With reference to  FIGS. 26I-K , while displaying the locked interface  2620 , the electronic device  2600  detects a user input  2628  ( FIG. 26I ), for instance, near an edge of the display  2602 . The user input  2628  is a swipe gesture that, in some examples, is a request to access a home screen interface of the electronic device  2600 . In some examples, the electronic device  2600  receives the user input  2628  prior to completing an initial biometric authentication (e.g., biometric authentication performed in response to a wake condition, as described with reference to  FIGS. 21A-C ). Accordingly, in response to the swipe input  2628 , the electronic device displays (e.g., replaces display of the locked interface  2620  with) the interstitial interface  2630  of  FIG. 26K  to indicate that the electronic device has not yet completed biometric authentication. In some examples, displaying the interstitial interface  2630  includes sliding the locked interface  2620  in an upward direction to display (e.g., reveal) the interstitial interface  2630 , as analogously described with reference to  FIGS. 19P-R . The interstitial interface  2630  includes a locked state indicator  2624  in some examples. 
     Alternatively, in some examples, the electronic device determines that a threshold number (e.g., 5) of biometric authentication attempts has been reached. Thereafter, in response to the user input  2628 , the electronic device  2600  displays the interstitial interface  2632 . The interstitial interface includes a biometric authentication enablement indicator indicating that biometric authentication is disabled (e.g., because the number of attempts has been reached). The interstitial interface  2632  further includes alternative authentication affordances  2636  and  2638 . Activation of the alternative authentication affordance  2636  causes the electronic device to display a first alternative authentication interface, such as a fingerprint authentication interface, and activation of the alternative authentication affordance  2638  causes the electronic device to display a second alternative authentication interface, such as a passcode authentication interface. 
     In some examples, while displaying the interstitial interface  2630 , the electronic device detects biometric data (e.g., facial biometric data) and, in response, performs biometric authentication. With reference to  FIG. 26M , the electronic device  2600  displays the biometric progress indicator  2625  to indicate that the biometric data is being processed. 
     In  FIG. 26N , the electronic device  2600  determines that the biometric authentication is successful. In response, the electronic device  2600  displays the unlocked state indicator  2626  and, optionally, outputs a tactile output  2640 . After indicating that the biometric authentication was successful (e.g., after a predetermined amount of time), the electronic device displays (e.g., replaces display of the interstitial interface  2630  with) the home screen interface  2614  of  FIG. 26P . With reference to  FIGS. 21O-P , in some examples, displaying the home screen interface  2614  includes sliding the home screen interface  2614 , as analogously described with reference to  FIGS. 19P-R . 
     Alternatively, in  FIG. 26Q , the electronic device  2600  determines that the biometric authentication was not successful. In response, the electronic device  2600  alternates a position of the locked state indicator  2627  to simulate a “shake” effect. The electronic device  2600  further outputs a tactile output  2644  to indicate the biometric authentication was unsuccessful. In some examples, the tactile output  2644  is the same as the tactile output  2640 . In some examples, the tactile output  2644  is different than the tactile output  2640 . In some examples, in response to determining the biometric authentication was unsuccessful, the electronic device displays an alternative authentication affordance  2642 . 
     With reference to  FIG. 26R , the electronic device receives an activation of the locked state indicator  2624 . In some examples, activation of the locked state indicator is a tap gesture  2650  on the locked state indicator  2624 . In response, as shown in  FIG. 26S , the electronic device  2600  initiates biometric authentication. In some examples, initiating biometric authentication includes obtaining (e.g., capturing with the one or more biometric sensors  2603 ) data corresponding to at least a portion of the biometric feature and processing the biometric data to determine whether the biometric feature (or a portion thereof) satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template). While processing the biometric data, the electronic device displays (e.g., replaces display of the locked state indicator  2624  with) biometric progress indicator  2625 , indicating that the electronic device  2600  is processing biometric data. If the electronic device  2600  determines that biometric authentication is successful, the electronic device indicates the success, as described with respect to  FIGS. 26N-P . 
     In  FIG. 26T , the electronic device  2600  determines that biometric authentication (e.g., as described with reference to  FIG. 26S ) was unsuccessful, and in response, alternates a position of the locked state indicator to simulate a “shake” effect, outputs a tactile output  2652 , and displays an alternative authentication affordance  2642 . 
     In  FIG. 26U , the electronic device detects an activation of the alternative authentication affordance  2642 . In some examples, the activation of the alternative authentication affordance is a tap gesture  2654  on the alternative authentication affordance  2642 . With reference to  FIG. 26V , in response to activation of the alternative authentication affordance  2642 , the electronic device displays (e.g., replaces display of the interstitial interface  2630  with) alternative authentication interface  2656 , with which a user authenticates with the electronic device upon entry of a valid passcode (or password). 
     With reference to  FIGS. 26W-Y , in some examples, the electronic device fails to detect a biometric feature for a predetermined amount of time, the electronic device displays one or more interfaces and/or enters a low power state. In  FIG. 26W , the electronic device displays interstitial interface  2630  (recall that the electronic device displays interstitial interface  2630  in response to a request for secured content received prior to completion of biometric authentication). If, for a predetermined amount of time, the electronic device  2600  does not detect a biometric feature, the electronic device displays (e.g., replaces display of the interstitial interface  2630  with) alternative authentication interface  2657 . In some examples, the alternative authentication interface  2657  includes an indicator instructing the user to provide alternative authentication, such as a passcode. In other examples, as shown in  FIG. 26X , the alternative authentication interface  2657  does not include an indicator instructing the user to provide the alternative authentication. 
     If during display of the alternative authentication interface  2657 , a biometric feature is not detected for a predetermined amount of time, and no alternative authentication is provided, the electronic device  2600  transitions to a low-power state (e.g., display-disabled state), as shown in  FIG. 26Y . 
     If, during display of the alternative authentication interface  2657 , a biometric feature is detected, the electronic device  2600  performs biometric authentication, as described. As shown in  FIG. 26Z , the electronic device displays (e.g., replaces display of the locked state indicator  2624  with) biometric progress indicator  2625  to indicate the electronic device is processing biometric data. In  FIG. 26AA , the electronic device  2600  determines that biometric authentication is successful. In response, the electronic device displays (replaces display of biometric progress indicator  2625  with) unlocked state indicator  2610  and, optionally, outputs a tactile output  2658  to indicate that the biometric authentication is successful. In some examples, the electronic device  2600  subsequently displays a home screen interface  2614 , as shown in  FIG. 26AB . 
     With reference to  FIGS. 26AC -AE, if during display of the alternative authentication interface  2657 , biometric authentication fails, and at least a portion of an alternative authentication is provided, the electronic device  2600  indicates that the biometric authentication is unsuccessful without providing a tactile output. As shown in  FIG. 26AC , the electronic device, while performing biometric authentication (as indicated by biometric progress indicator  2625 ), receives a portion of an alternative authentication (e.g., passcode) by way of user input (e.g., tap gesture)  2660 . In  FIG. 26AD , the electronic device determines that the biometric authentication was unsuccessful, and in response, displays the locked state indicator  2627  and further alternates a position of the locked state indicator to simulate a “shake” effect. In some examples, the electronic device  2600  does not output a tactile output, and further maintains display of the alternative authentication interface  2657 , as shown in  FIG. 26AE . 
     In  FIG. 26AF , the electronic device  2600 , while in a locked state, displays locked interface  2620 . As described, the locked interface  2620  includes a notification affordance  2622  and a locked state indicator  2624 . In some examples, the electronic device receives a request for secured content on the electronic device (e.g., a message associated with notification affordance  2622 ). The electronic device  2600 , for instance, detects activation of the notification affordance  2622 . In some examples, the activation of the notification affordance  2622  is a tap gesture  2662 . 
     In some examples, the activation of the notification affordance  2622  is received prior to completion of biometric authentication. Accordingly, as shown in  FIG. 26AG , in response to the activation of the notification affordance  2622 , the electronic device  2600  displays interstitial interface  2629  including a biometric indicator  2666 . The biometric indicator  2666  identifies secured content associated with the received request for secured content in some examples. 
     As shown in FIG. AH, if, while displaying the interstitial interface  2629 , the electronic device  2600  does not detect a biometric feature, the electronic device displays an alternative authentication affordance  2668 . In some examples, activation of the alternative authentication affordance  2668  causes the electronic device to display an alternative authentication interface (e.g., alternative authentication interface  2657  of  FIG. 26X ). 
     If during display of the alternative authentication interface, a biometric feature is not detected for a predetermined amount of time, and no alternative authentication is provided, the electronic device  2600  transitions to a low-power state (e.g., display-disabled state), as shown in  FIG. 26AI . 
     As described with respect to FIG. AH, the electronic device displays alternative authentication affordance  2668  if no biometric feature is detected. In some examples, a biometric feature is detected after display of alternative authentication affordance  2668 , and in response, the electronic device performs biometric authentication, as described above. As shown in FIG. AJ, to indicate that biometric data is being processed, the electronic device  2600  displays biometric progress indicator  2625 . In  FIG. 26AK , the electronic device  2600  determines that biometric authentication is successful. In response, the electronic device  2600  display unlocked state indicator  2610 , and, optionally, provides tactile output  2670  to indicate that the biometric authentication was successful. In some examples, the electronic device  2600  subsequently displays a messaging application interface  2616 , as shown in  FIG. 26AM . With reference to  FIGS. 26AL -AM, some examples, displaying the messaging application interface  2616  includes sliding the interstitial interface  2629  in an upward direction to display (e.g., reveal) messaging application interface  2616 , as analogously described with reference to  FIGS. 19P-R . 
     In  FIG. 26AN , the electronic device  2600  displays the interstitial interface  2629  having the alternative authentication affordance  2668 . While displaying the interstitial interface  2629 , the electronic device detects activation of the alternative authentication affordance  2668 . In some examples, the activation of the alternative authentication affordance  2668  is a tap gesture  2674  on the alternative authentication affordance  2668 . 
     With reference to  FIG. 26AO , in response to activation of the alternative authentication affordance  2668 , the electronic device  2600  displays alternative authentication interface  2631 . In some examples, the alternative authentication interface  2631  identifies requested secured content (“Enter passcode for messages”). 
     With reference to  FIGS. 26AP -AQ, a valid passcode (or password) is received by the electronic device  2600 , at least in part, in response to the tap gesture  2076  ( FIG. 26AP ), and optionally, one or more other inputs indicating additional alphanumeric digits of the valid passcode. As shown in  FIGS. 26AR -AS, once a valid passcode has been received, the electronic device is unlocked and displays (e.g., replaces display of the alternative authentication interface  2631  with) the messaging application interface  2616 . In some examples, displaying the messaging application interface  2616  includes sliding the alternative authentication interface  2631  in an upward direction to display (e.g., reveal) the messaging application interface  2616 , as analogously described with reference to  FIGS. 19P-R . 
       FIGS. 27A-27E  are a flow diagram illustrating a method for performing biometric authentication using an electronic device in accordance with some examples. Method  2700  is performed at a device (e.g.,  100 ,  300 ,  500 ,  2600 ) with a display, one or more input devices (e.g., a touchscreen, a mic, a camera), and a wireless communication radio (e.g., a Bluetooth connection, WiFi connection, a mobile broadband connection such as a 4G LTE connection). In some examples, the display is a touch-sensitive display. In some examples, the display is not a touch sensitive display. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In some examples, the device includes one or more biometric sensors which, optionally, include a camera, such as a infrared camera, a thermographic camera, or a combination thereof. In some examples, the device further includes a light-emitting device, such as an IR flood light a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of the biometric feature by the one or more biometric sensors. Some operations in method  2700  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  2700  provides an intuitive way for performing biometric authentication. The method reduces the cognitive burden on a user for authentication of biometric features, thereby creating a more efficient human-machine interface and intuitive user experience. For battery-operated computing devices, enabling a user to performing authentication of biometric features faster and more efficiently conserves power and increases the time between battery charges. 
     In some examples, while the electronic device (e.g.,  2700 ) is in a locked state in which the device is not authorized to perform a respective operation, the electronic device displays a first graphical indication (e.g.,  2624 ) (e.g., a closed lock icon) that indicates that the device is in the locked state. Displaying a first graphical indication that indicates that the device is in the locked state provides the user with a readily available indication as to the state of the device. In turn, the user is informed as to what functions of the device are enabled and/or available, thereby making the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, while the device is in an unlocked state in which the device is authorized to perform the respective operation, displaying a second graphical indication (e.g.,  2610 ) (e.g., an open lock icon) that indicates that the device is in the unlocked state in place of the first graphical indication. Displaying a second graphical indication that indicates that the device is in the unlocked state provides the user with a readily available indication as to the state of the device. In turn, the user is informed as to what functions of the device are enabled and/or available, thereby making the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the first graphical indication and the second graphical indication are displayed at a respective location (e.g., substantially near the top-center of the display  2602 ) in a user interface (e.g.,  2606 ,  2620 ). 
     In some examples, the electronic device detects ( 2702 ) a request to perform a respective operation that requires authentication. In some examples, the request to perform a respective operation that requires authentication is a request (e.g.,  2612 ) to display a home screen (e.g.,  2614 ) with a plurality of application open icons that, when selected, open corresponding applications, or a request to display an application user interface corresponding to a selected notification. In some examples, the request to perform a respective operation includes a home input (e.g.,  2612 ). In some examples, the home input is a selection of a home button or a home gesture, such as an upward swipe from a respective edge of the display, such as a bottom of the display. In some examples, the request to perform a respective operation includes selection (e.g.,  2615 ) of a notification (e.g.,  2608 ). In some examples, the selection of a notification is a tap, long press, hard press, or swipe on a notification user interface object. In some examples, the respective operation includes displaying a home screen that includes a plurality of application icons for opening different applications. In some examples, the plurality of application icons for opening different applications are application icons that, when selected cause a corresponding application to be opened. In some examples, the home screen also includes one or more widgets, system status indicators, device controls, etc. In some examples, the respective operation includes displaying an application user interface (e.g.,  2616 ) for an application that corresponds to the notification. In some examples, the application interface includes information specifically related to the notification (e.g., the notification is a notification of an electronic communication and the application user interface includes a representation of the electronic communication or the notification). 
     In response to detecting the request to perform the respective operation that requires authentication ( 2704 ), in accordance with a determination that the device is unlocked, the electronic device performs ( 2706 ) the respective operation. Further, in accordance with a determination that the device is locked and a first form of authentication is available for use ( 2708 ), the electronic device displays ( 2712 ), on the display (e.g.,  2602 ), an authentication indicator (e.g.,  2625 ) for the first form of authentication without displaying one or more affordances (e.g.,  2636 ,  2638 ) for using a second form of authentication. Displaying the authentication indicator without displaying affordances for using a second form of authentication provides the user with an intuitive interface in which the device forgoes providing additional options while biometric authentication is performed. Providing an intuitive interface in this manner enhances the operability of the device (e.g., avoids a user attempting alternative authentication prior to completion of biometric authentication) and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the authentication indicator is a visual indication that the first form of authentication is being attempted by the device, such as text or graphical elements describing the first form of authentication (e.g., password, passcode, fingerprint, or other form of authentication). In some examples, the first form of authentication is a form of biometric authentication based on data obtained by the one or more biometric sensors ( 2710 ) (e.g., a contactless form of biometric authentication such as face recognition or iris recognition). In some examples, the authentication indicator includes information indicating that the device is attempting to use first form of authentication ( 2714 ). In some examples, the authentication indicator includes a graphic or text description indicating that face biometric authentication is available such as “Face ID” or “Face ID to open Messages”). In some examples, the authentication indicator is displayed along with an option to cancel authentication. In some examples, the authentication indicator is displayed along with an option to display emergency information (e.g., an emergency call user interface and/or emergency medical information) without unlocking the device. In some examples, the authentication indicator includes information of progress of an attempt at the first form of authentication ( 2716 ), such as a progress indicator as described in greater detail with respect to  FIGS. 11A-11O . 
     In some examples, while displaying the authentication indicator for the first form of authentication without displaying affordances for using the second form of authentication, the electronic device processes ( 2718 ) respective data from the one or more biometric sensors (e.g.,  2603 ). In some examples, at least a portion of the respective data from the one or more biometric sensors, that is processed while displaying the biometric authentication indicator for the first form of biometric authentication without displaying one or more affordances for using the second form of authentication, was obtained by the one or more biometric sensors prior to displaying the authentication indicator for the first form of authentication ( 2720 ). In some examples, at least a portion of the respective data from the one or more biometric sensors, that is processed while displaying the biometric authentication indicator for the first form of biometric authentication without displaying one or more affordances for using the second form of authentication, was obtained by the one or more biometric sensors after displaying the authentication indicator for the first form of authentication ( 2722 ). 
     In some examples, after processing the respective data from the one or more biometric sensors ( 2724 ), in accordance with a determination that the respective data from the one or more biometric sensors is consistent with biometric information that is authorized to perform the respective operation (e.g., the device detects an authorized face in the respective biometric data), the electronic device performs ( 2726 ) the respective operation. Performing the respective operation in response to determining that the respective data from the one or more biometric sensors is consistent with biometric information that is authorized to perform the respective operation enhances the operability of the device by, in some examples, allowing a user to authenticate with a device without having to manually authenticate, thereby making the user-device interface more efficient. 
     In some examples, further after processing the respective data from the one or more biometric sensors, in accordance with a determination that the respective data is not consistent with biometric information that is authorized to perform the respective operation ( 2728 ) (e.g., the device detects no face or detects a face that is not consistent with authorized faces), the electronic device displays ( 2730 ) one or more affordances (e.g.,  2636 ,  2638 ) for using the second form of authentication that were not displayed prior to processing the respective data from the one or more biometric sensors. Displaying the one or more affordances for using the second form of authentication that were not displayed prior to processing the respective data from the one or more biometric sensors provides the user with a quick alternative method to access operations (e.g., locked operations) of the device that require successful authentication when the biometric data is unsuccessful. Providing additional control options with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the one or more affordances includes displaying a “use passcode” button, a “use password” button, or a keypad/keyboard for entering a passcode/password. In some examples, the one or more affordances for using the second form of authentication are displayed after a respective delay during which the authentication indicator for the first form of authentication is displayed without displaying one or more affordances for using a second form of authentication. 
     In some examples, displaying the one or more affordances includes: in accordance with a determination that a biometric feature that corresponds to the first form of authentication is detected by the one or more biometric sensors, displaying the one or more affordances for using the second form of authentication after a first time period has elapsed (e.g., since the authentication indicator was displayed); and in accordance with a determination that no biometric feature that corresponds to the first form of authentication is detected by the one or more biometric sensors, displaying the one or more affordances for using the second form of authentication after a second time period has elapsed (e.g., since the authentication indicator was displayed). In some examples, the second time period is different from (e.g., longer than or shorter than) the first time period. 
     In some examples, displaying the one or more affordances includes: in accordance with a determination that a biometric feature that can be used in the first form of authentication but that is not consistent with authorized biometric features has been detected, displaying the user interface (e.g.,  2656 ) for the second form of authentication (e.g., displaying a plurality of character entry keys (e.g., a keyboard or keypad) for entering a sequence of characters for authentication (e.g., a password or passcode)) concurrently with respective instructions to provide one or more inputs to authenticate with the second form of authentication (e.g., displaying the instructions to use the one or more character entry keys to enter the sequence of characters for authentication (e.g., the passcode keypad is displayed with “enter passcode to unlock” instructions)); and in accordance with a determination that no biometric feature that corresponds to the first form of authentication has been detected by the one or more biometric sensors, displaying the user interface (e.g.,  2657 ) for the second form of authentication (e.g., displaying a plurality of character entry keys (e.g., a keyboard or keypad) for entering a sequence of characters for authentication (e.g., a password or passcode)) without displaying the respective instructions to provide one or more inputs to authenticate with the second form of authentication. In some examples, the user interface for the second form of authentication is displayed without displaying the respective instructions to use the one or more character entry keys to enter the sequence of characters for authentication (e.g., the passcode keypad is displayed without “enter passcode to unlock” instructions)). In some examples, the plurality of character entry keys are initially displayed without the respective instructions to use the one or more character entry keys to enter the sequence of characters for authentication (e.g., while the device is attempting to use the first form of authentication) and then, when using the first form of authentication fails, the device displays explicit instructions to use the one or more character entry keys to enter the sequence of characters for authentication. 
     In some examples, displaying the one or more affordances includes: in accordance with a determination that the request to perform the respective operation includes a home input, displaying a plurality of character entry keys (e.g., a keyboard or keypad) for entering a sequence of characters for authentication (e.g., a password or passcode); and in accordance with a determination that the request to perform the respective operation includes selection of a notification, displaying a passcode affordance that, when activated causes display of a plurality of character entry keys (e.g., a keyboard or keypad) for entering a sequence of characters for authentication (e.g., a password or passcode). In some examples, the passcode affordance is restricted from activation in response to tap inputs and is responsive to one or more other types of inputs that include additional input requirements beyond a touch input. In some examples, the one or more additional input requirements include a requirement that the input is a hard press input (e.g., a requirement that the input reach a characteristic intensity that is above a respective intensity threshold), a requirement that the input is a long press input (e.g., a requirement that the input include a contact that is maintained on the touch-sensitive surface for more than a predetermined amount of time without moving more than a predetermined distance), and/or a requirement that the input is a swipe input (e.g., a requirement that the input include movement of a contact by more than a threshold amount of movement in a respective direction). Restricting activation in response to tap inputs in this manner avoids spurious (e.g., accidental and/or unintentional) activations of the passcode affordance, providing improved control and usability of the electronic device, thereby reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, after displaying one or more affordances for using the second form of authentication that were not displayed prior to processing the respective data from the one or more biometric sensors: in accordance with a determination that the request to perform the respective operation includes a home input, the electronic device waits for additional input for a first delay time period before (automatically, without further user input) ceasing to display the one or more affordances for using the second form of authentication (e.g., turning off the display); and in accordance with a determination that the request to perform the respective operation includes selection of a notification, the electronic device waits for additional input for a second delay time period before (automatically, without further user input) ceasing to display the one or more affordances for using the second form of authentication (e.g., turning off the display). In some examples, the second delay time period is different from (e.g., shorter than or longer than) the first delay time period. 
     In some examples, while the device is locked and a first form of authentication is available for use, the electronic device attempts ( 2732 ) biometric authentication using the first form of authentication. In some examples, the device is locked and/or a first form of authentication is available for use in response to the request to perform the respective operation, in response to an attempt to use the second form of authentication, or in response to an input requesting authentication such as lifting the device, pressing a button (e.g.,  2604 ) on the device, tapping a lock icon on the device, or tapping a touch-sensitive display of the device). In some examples, while attempting the biometric authentication using the first form of authentication, the electronic device displays ( 2734 ) a progress indicator (e.g., as depicted by progress indicators  2624  and/or  2625 ) that changes appearance to indicate progress toward biometric authentication using the first form of authentication. In some examples, the electronic progress indicator is a progress bar or an icon that changes from a “face detection” icon or an animation to a “face analysis” icon or animation. In some examples, while attempting the biometric authentication using the first form of authentication, the device replaces the first graphical indication with a progress indicator. In some examples, after completing an attempt at the first form of authentication, in accordance with a determination that the authentication was unsuccessful, the electronic device replaces the progress indicator with the first graphical indication (e.g., the closed lock icon); and in accordance with a determination that the authentication was successful, the electronic device replaces the progress indicator with the second graphical indication (e.g., the open lock icon). 
     In some examples, after attempting the biometric authentication using the first form of authentication ( 2736 ), in accordance with a determination that the biometric authentication with the first form of authentication is successful, the electronic device updates ( 2738 ) the progress indicator in a first manner (e.g., displaying a check mark or an open lock icon) to indicate the successful authentication with the first form of authentication (and, optionally, performing the respective operation); and/or generates a second tactile output (e.g., that is different from the first tactile output that indicates authentication failure) that indicates an authentication success (e.g., a single tap). 
     In some examples, after attempting the biometric authentication using the first form of authentication, in accordance with a determination that the biometric authentication with the first form of authentication detects a biometric feature that can be used in the first form of authentication but that is not consistent with authorized biometric features, the electronic device updates ( 2740 ) the progress indicator in a second manner (e.g., shaking a lock icon or face icon side to side to indicate that authentication failed) to indicate unsuccessful authentication. In some examples, the second manner of updating the progress indicator is different from the first manner of updating the progress indicator ( 2742 ). In some examples, the electronic device generates a first tactile output that indicates an authentication failure (e.g., a triple tap). 
     In some examples, after attempting the biometric authentication using the first form of authentication, in accordance with a determination that the biometric authentication with the first form of authentication does not detect a biometric feature that can be used in the first form of authentication, the electronic device updates ( 2744 ) the progress indicator in a third manner (e.g., displaying a closed lock icon without shaking the lock icon side to side to indicate that authentication failed) that is different from the first manner and the second manner. 
     In some examples, after attempting the biometric authentication using the first form of authentication, in accordance with a determination that the biometric authentication with the first form of authentication does not detect a biometric feature that can be used in the first form of authentication, the electronic device displays a graphical indication that a successful authentication has not occurred without generating a tactile output. In some examples, the device does not generate the first tactile output or another tactile output that indicates an authentication failure, because the device did not recognize any biometric feature that could be used for the first form of authentication). 
     In some examples, after attempting the biometric authentication using the first form of authentication for a first time: the electronic device displays a user interface (e.g.,  2654 ) for the second form of authentication that includes a plurality of character entry keys (e.g., a keyboard or keypad) for entering a sequence of characters for authentication (e.g., a password or passcode). Further, the electronic device, while displaying the user interface for the second form of authentication, attempts the biometric authentication using the first form of authentication for a second time. Further, in accordance with a determination that the biometric authentication with the first form of authentication is successful, the electronic device performs the respective operation (and, optionally, updates the progress indicator in a first manner (e.g., displaying a check mark or an open lock icon (e.g.,  2610 )) to indicate the successful authentication with the first form of authentication). Further, in accordance with a determination that the biometric authentication with the first form of authentication detects a biometric feature that can be used in the first form of authentication but that is not consistent with authorized biometric features before receiving input entering less than a threshold number of characters (e.g., less than 1, 2, 3, 4, or 5 characters) via one or more of the plurality of character entry keys, the electronic device forgoes performing the respective operation and generates a first tactile output that indicates an authentication failure (e.g., a triple tap) (and, optionally, displays a graphical indication that a successful authentication has not occurred). Further, in accordance with a determination that the biometric authentication with the first form of authentication detects a biometric feature that can be used in the first form of authentication but that is not consistent with authorized biometric features after receiving input entering at least the threshold number of characters (e.g., less than 1, 2, 3, 4, or 5 characters) via one or more of the plurality of character entry keys, the electronic device performs the respective operation and displays a graphical indication that a successful authentication has not occurred without generating a tactile output (e.g., a closed lock icon). 
     In some examples, in response to detecting the request to perform the respective operation that requires authentication: in accordance with a determination that the device is locked and the first form of biometric authentication is not available for use (e.g., when the request to perform the respective operation is received), the electronic device displays ( 2746 ) one or more affordances for using the second form of authentication (e.g., a passcode or password entry user interface or a prompt to use a second form of biometric authentication such as a fingerprint authentication). In some examples, the first form of authentication is not available for use because it has been disabled ( 2748 ). In some examples, the first form of authentication is not available for use due to more than a threshold number of failed biometric authentication attempts with the first form of biometric authentication, due to a restart of the device, or due to a user request to disable the first form of biometric authentication. In some examples, the first form of authentication is disabled in response to user entry into an emergency option user interface without selecting an option that corresponds to a request to access additional information at the device (e.g., the user triggers display of the emergency option user interface by pressing two or more buttons concurrently for more than a threshold amount of time and then selects an option to shut down the device or cancel display of the emergency option user interface rather than selecting an option to display medical information or display an emergency dialing interface). In some examples, the first form of authentication is disabled in response to user selection of an option to disable the first form of biometric authentication (e.g., via a biometric authentication setting in a settings user interface). In some examples, the first form of authentication is not available for use because operation of the one or more biometric sensors is limited by current environmental and/or device conditions that reduce the ability of the one or more biometric sensors to operate within predefined parameters ( 2750 ). In some examples, the device is too hot, the device is too cold, there is too much light in an environment of the device, there is too little light in the environment of the device, and/or the battery of the device is not sufficiently charged to run the one or more biometric sensors. 
     In some examples, the electronic device detects a first input (e.g.,  2650 ) (e.g., a tap input) at a location that corresponds to the respective location in the user interface. In some examples, in response to detecting the first input at the location that corresponds to the respective location in the user interface, in accordance with a determination that the device is in a locked state (e.g., the tap input was detected on the closed lock icon), the electronic device attempts the first form of authentication. Attempting the first form of authentication in response to detecting the first input at the location that corresponds to the respective location in the user interface and in accordance with a determination that the device is in a locked state provides an intuitive and convenient feature in which the first form of authentication is initiated, thereby making the user-device interface more efficient, which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device detects a second input (e.g., a tap input) at a location that corresponds to the respective location in the user interface. In some examples, in response to detecting the second input at the location that corresponds to the respective location in the user interface, in accordance with a determination that the device is in an unlocked state (e.g., the tap input was detected on the open lock icon), the electronic device transitions the device from the unlocked state to the locked state. In some examples, the respective location is on a cover sheet user interface that is displayed when the device screen is initially turned on, and the second graphical indication (e.g., the open lock icon) is displayed when the cover sheet user interface is displayed on the device while the device is still in the unlocked state, while the first graphical indication (e.g., the lock icon) is displayed when the cover sheet user interface is displayed on the device while the device is in the locked state. 
     Note that details of the processes described above with respect to method  1200  (e.g.,  FIGS. 27A-27E ) are also applicable in an analogous manner to the methods described herein. For example, method  2700  optionally includes one or more of the characteristics of the various methods described herein with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  1800 ,  2000 ,  2200 , and  2500 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to  FIGS. 26L-N . For another example, one or more interstitial interfaces as described in methods  2000  and  2700  optionally are displayed in response to receipt of an input prior to completion of a biometric authentication process. For brevity, these details are not repeated herein. 
     The operations in the information processing methods described above are, optionally, implemented by running one or more functional modules in an information processing apparatus such as general purpose processors (e.g., as described with respect to  FIGS. 1A, 3, and 5A ) or application specific chips. Further, the operations described above with reference to  FIGS. 27A-27E  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, detecting operation  2702 , performing operation  2706 , displaying operation  2712 , and display operation  2746  are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190 . Event monitor  171  in event sorter  170  detects a contact on touch-sensitive surface  604 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some examples, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS. 1A-1B . 
       FIGS. 28A-28AA  illustrate exemplary user interfaces for preventing retrying biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary examples of the user interfaces illustrated in  FIGS. 28A-28AA  are used to illustrate the processes described below, including the processes in  FIGS. 29A-29B . 
       FIG. 28A  illustrates electronic device  2800  (e.g., portable multifunction device  100 , device  300 , device  500 , or device  1700 ). In the exemplary examples illustrated in  FIGS. 28A-28AA , electronic device  2800  is a smartphone. In other examples, electronic device  2800  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  2800  includes display  2802 , one or more input devices (e.g., touchscreen of display  2802  and a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In  FIG. 28A , the electronic device includes biometric sensor  2803 . In some examples, the biometric sensor is one or more biometric sensors that can include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, biometric sensor  2803  is biometric sensor  703 . In some examples, the one or more biometric sensors include one or more fingerprint sensors (e.g., a fingerprint sensor integrated into a button). In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 28A , electronic device  2800  displays, on display  2802 , user interface  2804  of an application. The application is a mobile browser application, and user interface  2804  corresponds to a website (onlinestore.com). In  FIG. 28B , electronic device  2800  detects tap gesture  2806  on log-in affordance  2808 . Electronic device  2800  identifies tap gesture  2806  as a request to load log-in user interface  2810  (shown in  FIG. 28C ). Electronic device  2800  also identifies tap gesture  2806  as a request to autofill fillable fields, username field  2812  and password field  2814 , in log-in user interface  2810  with credential information (e.g., a username and password that enables a user to successfully log-in to an account). The request to autofill requires biometric authentication in order to proceed with autofilling the fillable fields. In some examples, the request also includes a request to automatically log-in the user such that the user does not need to tap a submit affordance (e.g.,  2860  in  FIG. 28Z ) in order to submit credentials and log-in. 
     In  FIG. 28C , in response to tap gesture  2806  (e.g., the request to autofill the fillable fields), electronic device  2800  uses biometric sensor  2803  to determine whether certain biometric authentication criteria have been met. Electronic device  2800  captures and processes (e.g., analyzes) the biometric data from biometric sensor  2803  to determine, based on the biometric data, whether the biometric feature (or a portion thereof) satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template). Biometric sensor  2803  is contactless such that the sensor is configured to perform biometric authentication without physical input from the user (e.g., without any additional gestures after tap gesture  2806 ). As a result, electronic device  2800  initiates biometric authentication using biometric sensor  2803  without needing to receive an explicit request from a user to initiate biometric authentication. 
     Performing biometric authentication includes displaying biometric authentication interface  2816  having biometric authentication glyph  2818 . Biometric authentication glyph  2818  is a simulation of a representation of a biometric feature (e.g., a face). As shown in  FIG. 28C , biometric authentication interface  2816  is overlaid on at least a portion of log-in user interface  2810 . Biometric authentication interface  2816 , optionally, is an operating system level interface (e.g., an interface generated by an operating system of the device), and log-in user interface  2810  is an application-level interface (e.g., a user interface generated by a third-party application that is separate from the operating system of the device). In some examples, the displayed biometric authentication interface is approximately centered along a horizontal and/or vertical axis such as in  FIGS. 28B-28E . In some examples, electronic device  2800  displays the biometric authentication interface at the top, bottom, side, or in a corner of display  2802 . For example, electronic device  2800  displays the biometric authentication interface near the top of display  2802 , such as in, for example,  FIG. 30AL . In some examples, electronic device  3000  does not display the biometric authentication interface while biometric authentication is being performed. 
     In  FIGS. 28D-28E , electronic device  2800  displays a biometric authentication animation including biometric authentication glyph  2820  in  FIG. 28D  and biometric authentication glyph  2822  in  FIG. 28E , which serve as a portion of the animation during which biometric sensor  2803  attempts to obtain biometric data. 
     In  FIG. 28F , a determination is made that biometric authentication has failed (e.g., biometric authentication criteria have not been met). As a result, electronic device  2800  forgoes autofilling username field  2812  and password field  2814 . Additionally, electronic device  2800  does not display an indication to the user that the user should re-attempt biometric authentication. In some examples, a determination is made that biometric authentication is successful (e.g., biometric authentication criteria have been met). As a result, in those examples, electronic device  2800  autofills username field  2812  and password field  2814 . 
     In  FIG. 28G , electronic device  2800 , after determining that biometric authentication has failed, detects tap gesture  2824  on reload affordance  2826 . Electronic device  2800  identifies tap gesture  2824  as a request to reload log-in user interface  2810 . Electronic device  2800  also identifies tap gesture  2824  as a request to autofill one or more fillable fields (e.g., username field  2812  and password field  2814 ) in log-in user interface  2810 . As described earlier, the request to autofill requires biometric authentication in order to proceed with autofilling the fillable fields. 
     In response to the request to autofill the fillable fields, a determination is made that the failure of biometric authentication in  FIG. 28F  was due to not detecting the presence of a face for a predetermined amount of time. As a result, electronic device  2800  uses biometric sensor  2803  to re-perform biometric authentication, as shown in  FIG. 28H . Electronic device  2800  re-performs biometric authentication automatically without needing a user to provide input to initiate the authentication. 
     In  FIGS. 28H-28I , electronic device  2800  performs biometric authentication, which includes displaying a biometric authentication interface and biometric authentication glyphs, as described with respect to  FIGS. 28C-28D . Once electronic device  2800  has obtained biometric data (e.g., obtained sufficient biometric data), electronic device transitions to displaying biometric authentication glyph  2828 . Electronic device  2800  displays biometric authentication glyph  2828  to indicate that the biometric data is being processed. In some examples, biometric authentication glyph  2828  includes a plurality of rings, which rotate spherically, for instance, while displayed. 
     In  FIG. 28K , a determination is made that biometric authentication has failed again. As a result, electronic device  2800  displays failed biometric authentication interface  2830  having failed biometric authentication glyph  2832 . As a result, electronic device  2800  forgoes autofilling username field  2812  and password field  2814 . In some examples, a determination is made that biometric authentication is successful. As a result, in those examples, electronic device  2800  autofills username field  2812  and password field  2814 . 
     In  FIG. 28L , electronic device  2800 , after determining that biometric authentication has failed for the second time, detects tap gesture  2824  on reload affordance  2826 . Electronic device  2800  identifies tap gesture  2826  as a request to reload log-in user interface  2810 . Electronic device  2800  also identifies tap gesture  2826  as a request to autofill one or more fillable fields (e.g., username field  2812  and password field  2814 ) in log-in user interface  2810 . As described earlier, the request to autofill requires biometric authentication in order to proceed with autofilling the fillable fields. 
     In response to the request to autofill the fillable fields, a determination is made that the failure of biometric authentication in  FIG. 28K  was due to detecting a face that was not consistent with an authorized face (e.g., the biometric data does not match, within a threshold, a biometric template). As a result, electronic device  2800  forgoes performing biometric authentication, as illustrated by  FIG. 28M . 
     In  FIG. 28N , electronic device  2800 , after forgoing to perform biometric authentication in response to tap gesture  2826 , detects tap gesture  2834  on username field  2812 . As a result, electronic device  2800  displays cursor  2836  in username field  2812  and also displays virtual keyboard  2838  and passwords affordance  2840 , as shown in  FIG. 28O . In  FIG. 28P , electronic device  2800  detects tap gesture  2842  on passwords affordance  2840 . As a result, electronic device  2800  displays a list of candidate input affordances (e.g.,  2844 ,  2846 , and  2848 ), as shown in  FIG. 28Q . In some examples, in response to detecting tap gesture  2834  on username field  2812 , electronic device  2800  displays an affordance labeled “usernames” instead of passwords affordance  2840 . 
     In  FIG. 28R , electronic device  2800  detects tap gesture  2850  on candidate input affordance  2848  (labeled “jj_appleseed@email.com”). Electronic device  2800  identifies tap gesture  2850  as a request to autofill username field  2812  and password field  2814  with credential information corresponding to candidate input affordance  2848 . This request to autofill the fillable fields is a different type of request to autofill than those resulting from a request to load or reload log-in user interface  2810 . A request to autofill via a request to load a log-in user interface is an implicit request, as the request to autofill is performed as part of the request to load the log-in user interface. In contrast, the request to autofill in  FIG. 28R  is an explicit request by the user to autofill username field  2812  and password field  2814  with credential information corresponding to candidate input affordance  2848 . In response to the request to autofill the fillable fields via the explicit request in  FIG. 28R , electronic device  2800  initiates biometric authentication, as shown in  FIG. 28S . 
     In  FIGS. 28S-28U , electronic device  2800  performs biometric authentication, which includes displaying a biometric authentication interface and biometric authentication glyphs, as described with respect to  FIGS. 28H-28J . 
     In  FIG. 28V , a determination is made that biometric authentication is successful. As a result, electronic device  2800  displays successful biometric authentication glyph  2852  indicating that biometric authentication was successful. 
     In  FIG. 28W , since biometric authentication was successful, electronic device  2800  autofills username field  2812  and password field  2814  with credential information corresponding to candidate input affordance  2848 . In some examples, a determination is made that biometric authentication has failed. As a result, in those examples, electronic device  2800  forgoes autofilling the username field  2812  and password field  2814  with the credential information. In some examples, upon failed biometric authentication, electronic device  2800  displays failure interface  2854  in  FIG. 28X , as described with respect to  FIG. 17M . Alternatively, electronic device  2800  can display failure interface  2856  in  FIG. 28Y , as described with respect to  FIG. 15S . Failure interface  2854  can be displayed when a user has not reached the maximum number of failed biometric authentication attempts (e.g., a maximum number of failed attempts without an intervening successful authentication attempt). When the maximum number of failed biometric authentication attempts has been reached, failure interface  2856  can instead be displayed. 
     After electronic device  2800  autofills username field  2812  and password field  2814  in  FIG. 28W , electronic device detects tap gesture  2858  on submit affordance  2860 , as illustrated by  FIG. 28Z . Electronic device  2800  identifies tap gesture  2858  as a request to submit the credential information in username field  2812  and password field  2814  for user authentication. Upon successful user authentication, electronic device  2800  provides access to restricted content (e.g., content that can only be seen once a user has logged in) in user interface  2862  of  FIG. 28AA . 
       FIGS. 29A-29B  are a flow diagram illustrating a method for re-performing biometric authentication after an initial unsuccessful biometric authentication attempt using an electronic device in accordance with some examples. Method  2900  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) with one or more biometric sensors (e.g.,  2803 ) (e.g., a fingerprint sensor, a contactless biometric sensor (e.g., a biometric sensor that does not require physical contact, such as a thermal or optical facial recognition sensor), an iris scanner). In some examples, the one or more biometric sensors (e.g.,  2803 ) include one or more cameras. The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) optionally includes a display (e.g.,  2802 ). In some examples, the display (e.g.,  2802 ) is a touch-sensitive display. In some examples, the display (e.g.,  2802 ) is not a touch sensitive display. 
     Some operations in method  2900  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. As described below, method  2900  provides an intuitive way for re-performing biometric authentication after an initial unsuccessful biometric authentication attempt. The method reduces the cognitive burden on a user for authenticating on an electronic device thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to authenticate faster and more efficiently conserves power and increases the time between battery charges. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) receives ( 2902 ) a first request (e.g.,  2806 ) to perform a respective operation that requires authentication (e.g., autofill, unlock device, make payment). In some examples, the first request (e.g.,  2806 ) is associated with performance of the respective operation. In some examples, the first request (e.g.,  2806 ) is also a request to perform a second operation, different than the respective operation (e.g., a request to display a webpage (e.g.,  2810 ) or load content that requires authentication). In some examples, the second operation does not require authentication. 
     In accordance with some examples, the first request (e.g.,  2806 ) is also a request to perform an operation that does not require biometric authentication. In response to receiving the first request (e.g.,  2806 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) performs the operation that does not require biometric authentication. 
     In accordance with some examples, the first request (e.g.,  2806 ) is a request to open a webpage (e.g.,  2810 ). 
     In response ( 2904 ) to receiving the first request (e.g.,  2806 ) to perform the respective operation, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) proceeds to blocks  2906 - 2910 . 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) uses ( 2906 ) the one or more biometric sensors (e.g.,  2803 ) to determine whether biometric authentication criteria are met, wherein the biometric authentication criteria include a requirement that a biometric feature of a respective type (e.g., a face or fingerprint) that is authorized to perform the respective operation is detected by the biometric sensors (e.g.,  2803 ). In some examples, the biometric authentication criteria include a requirement that an authorized biometric feature is detected by the one or more biometric sensors (e.g.,  2803 ). 
     In accordance with a determination that the biometric authentication criteria are met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) performs ( 2908 ) the respective operation. 
     In accordance with ( 2910 ) a determination that the biometric authentication criteria are not met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) forgoes ( 2912 ) performing the respective operation. Forgoing (or performing) the respective operation based on not meeting biometric authentication criteria provides security and can prevent unauthorized users from initiating sensitive operations. Providing improved security enhances the operability of the device and makes the user-device interface more efficient (e.g., by restricting unauthorized access) which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     In accordance with some examples, further in response ( 2904 ) to receiving the first request (e.g.,  2806 ) to perform the respective operation and in accordance with ( 2910 ) the determination that the biometric authentication criteria are not met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) forgoes ( 2914 ) displaying, on the display (e.g.,  2802 ), an indication to re-attempt authentication using the one or more biometric sensors (e.g.,  2803 ) (e.g., visually presented instructions that prompt the user to re-attempt biometric authentication). In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) also forgoes displaying an indication to re-request the respective operation. 
     In accordance with some examples, determining whether the biometric authentication criteria are met includes determining whether at least a portion of a biometric feature, determined based on data obtained from the one or more biometric sensors (e.g.,  2803 ) that correspond to the biometric feature, satisfies biometric authentication criteria. In some examples, when the request (e.g.,  2806 ) is also a request to perform the second operation that does not require authentication and is different than the respective operation, the second operation is performed even in accordance with a determination that the biometric authentication criteria are not met. For example, the first request (e.g.,  2806 ) (e.g., entry of a URL address) is a request to perform the respective operation (e.g., autofilling a username and/or password of the webpage (e.g.,  2810 ) associated with the URL address) that requires authentication and is also a request to perform a second operation (display of the webpage (e.g.,  2810 ) associated with the URL address) that does not require authentication. Performing the second operation that does not require authentication, even when the biometric authentication criteria are not met can provide the user with feedback to the request, even if the biometrically-secured operation is not performed. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     Subsequent to the determination that the biometric authentication criteria were not met in response to receiving the first request (e.g.,  2806 ) (e.g., no face was detected or a face that was detected is not consistent with an authorized face), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) receives ( 2916 ) a second request (e.g.,  2824 ) to perform the respective operation. In some examples, a non-user request to reload the webpage (e.g.,  2810 ) is not a request associated with retrying biometric authentication. 
     In response ( 2918 ) to receiving the second request (e.g.,  2824 ) to perform the respective operation, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) proceeds to blocks  2920 - 2922 . 
     In accordance with a determination that the biometric authentication criteria were not met in response to the first request (e.g.,  2806 ) due to the one or more biometric sensors (e.g.,  2803 ) not detecting the presence of a biometric feature of the respective type, using ( 2920 ) the one or more biometric sensors (e.g.,  2803 ) to determine whether the biometric authentication criteria are met in response to the second request (e.g.,  2824 ). Re-performing biometric authentication when a previous failure to authenticate was due to not detecting the presence of a biometric feature provides the user with the ability to re-attempt authentication without the need for additional inputs and without the need to clutter the user interface with additional displayed controls. Providing the ability to re-attempt authentication without additional input and without cluttering the UI with additional displayed controls enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the biometric feature is a face and data from the biometric sensors (e.g.,  2803 ) does not include data indicating that a face was detected. In some examples, the determination that the biometric authentication criteria were not met in response to the first request (e.g.,  2806 ) occurs when the one or more biometric sensors (e.g.,  2803 ) do not detect the presence of the biometric feature of the respective type for a predetermined amount of time. 
     In accordance with some examples, the determination that the biometric authentication criteria were not met in response to the first request (e.g.,  2806 ) due to the one or more biometric sensors (e.g.,  2803 ) not detecting the presence of a biometric feature of the respective type is a determination that the biometric authentication criteria were not met in response to the first request (e.g.,  2806 ) due to the one or more biometric sensors (e.g.,  2803 ) not detecting, for at least a predetermined time (e.g., a predetermined time after biometric authentication was triggered such as by the first request (e.g.,  2806 ) to perform the respective operation), the presence of a biometric feature of the respective type. 
     In accordance with a determination that the biometric authentication criteria were not met in response to the first request (e.g.,  2806 ) due to the one or more biometric sensors (e.g.,  2803 ) detecting a biometric feature of the respective type that does not correspond to the authorized biometric feature (e.g., a face that was detected is not consistent with an authorized face), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) forgoes ( 2922 ) using the one or more biometric sensors (e.g.,  2803 ) to determine whether the biometric authentication criteria are met in response to the second request (e.g.,  2824 ) (e.g., the device does not automatically retry biometric authentication in response to reloading webpage (e.g.,  2810 )). In some examples, forgoing re-performing biometric authentication further includes forgoing performing an operation that is performed if the biometric authentication criteria are met. Forgoing re-attempting biometric authentication when a previous failure to authenticate was due to detecting a biometric feature that is not authorized enhances security and reduces the instances of multiple resource-intensive re-attempts of a likely unauthorized user. Providing improved security enhances the operability of the device and makes the user-device interface more efficient (e.g., by restricting unauthorized access) which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     In accordance with some examples, subsequent to the determination that the biometric authentication criteria were not met in response to receiving the first request (e.g.,  2806 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) receives a third request (e.g.,  2850 ) (e.g., tap secured password field and select password to auto-fill, tap unsecured username field and select username to auto-fill) to perform the respective operation, wherein the third request is a different type of request (e.g., the third request is made using selection of a different affordance from that used to make the first and second requests, the third type of request is not also a request to perform a second operation (e.g., loading of a webpage) whereas the first and second request are also requests to perform the second operation) from the first request (e.g.,  2806 ) and the second request (e.g.,  2824 ). In response to receiving the third request (e.g.,  2850 ) to perform the respective operation, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) uses the one or more biometric sensors (e.g.,  2803 ) to determine whether the biometric authentication criteria are met in response to the third request (e.g.,  2850 ) (e.g., using the one or more biometric sensors to determine whether the biometric authentication criteria are met regardless of the reason that the biometric authentication criteria were not met in response to the first request (e.g.,  2806 ) (e.g., regardless of whether the biometric authentication criteria were not met due to the one or more biometric sensors detecting a biometric feature of the respective type that does not correspond to the authorized biometric feature or due to the one or more biometric sensors not detecting the presence of a biometric feature of the respective type). Re-performing biometric authentication after receiving a different type of request (e.g., an explicit request), regardless of the reason for a previous authentication failure provide the user with an ability to explicitly request re-authentication provides additional control options to the user. Providing additional control options to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, further in response to receiving the second request (e.g.,  2824 ) to perform the respective operation and in accordance with a determination that biometric authentication is not available (e.g. reached the maximum number of failed biometric authentication attempts, attempts since the last successful authentication have exceeded a predefined number of permitted attempts), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) prompts (e.g.,  2854 ,  2856 ) for an alternative form of authentication (e.g., a non-biometric form of authentication, such as a password or passcode). Providing a prompt (e.g., displaying a notification) for alternative authentication when biometric authentication is no longer available provides the user with feedback about the current state of the device and provides feedback to the user indicating what is required to authenticate. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) imposes a respective limit on the number of unsuccessful biometric authentication attempts that are permitted before an alternative form of authentication is required. The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) ceases to use the one or more biometric sensors (e.g.,  2803 ) to determine whether the biometric authentication criteria are met in response to requests to perform the respective operation after a predetermined number of requests to perform the respective operation (e.g., within a threshold time period) have resulted in failed biometric authentication attempts, wherein the predefined number of requests is less than the respective limit. 
     In some examples, in response to detecting a respective request to perform the respective operation, the device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) determines whether the predetermined number of requests to perform the respective operation have resulted in failed biometric authentication attempts. In accordance with a determination that the predetermined number of requests to perform the respective operation have resulted in failed biometric authentication attempts, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) forgoes attempting biometric authentication. In accordance with a determination that the predetermined number of requests to perform the respective operation have not resulted in failed biometric authentication attempts, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) proceeds with an additional biometric authentication attempt. 
     In some examples, the number of biometric authentication attempts or re-attempts that can be made (e.g., made without success) is limited to a pre-determined number of unsuccessful attempts before alternative authentication (e.g., password or passcode) is required. In such examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) forgoes re-attempting biometric authentication after a certain number of attempts, even under conditions where biometric authentication would otherwise be attempted (e.g., after a previous failure due to not detecting the presence of a biometric feature of the respective type) in order to not exceed the pre-determined number of allowable attempts.) Ceasing use of the biometric sensor (e.g., forgoing biometric authentication) prior to exhaustion of the permitted number of attempts after repeated requests avoids the user consuming the permitted number of attempts on repeated requests (e.g., repeated requests of the same type), conserving at least one attempt for requests for other operations that require biometric authentication. Conserving at least one attempt enhances the operability of the device and makes the user-device interface more efficient (e.g., by avoiding exhaustion of authentication attempts on repeated, similar requests) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, using the one or more biometric sensors (e.g.,  2803 ) to determine whether the biometric authentication criteria are met in response to the second request (e.g.,  2824 ) occurs automatically (e.g., without the need for an input from the user) in response to receiving the second request (e.g.,  2824 ) to perform the respective operation. 
     In accordance with some examples, the one or more biometric sensors (e.g.,  2803 ) are contactless biometric sensors (e.g.,  2803 ) (e.g., infrared camera, visible light camera, or combinations thereof) configured to perform biometric authentication without physical contact from the user. 
     In accordance with some examples, in response to the second request (e.g.,  2824 ) and in accordance with a determination that the biometric authentication criteria are met in response to the second request (e.g.,  2824 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) performs the respective operation (e.g., operation includes autofill, access data, unlock device, and/or make payment). 
     In accordance with some examples, the respective operation is autofilling one or more fillable fields (e.g.,  2812 ,  2814 ) with credential information. (e.g., credit card information or log-in information). In some examples, credit card information includes information associated with a payment account information (e.g., credit card, bank account, or payment service information). In some examples, log-in information includes information required to log-in to an application, an account, or a website (e.g.,  2862 ). Autofilling credential information upon a request and successful authentication provides the user with a capability to populate credentials without requiring further inputs (beyond the request). Performing an operation when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, the respective operation is providing access to restricted content. (e.g., logging in to a webpage (e.g.,  2862 ), displaying a list of passwords associated with a user, displaying credit card information). 
     In accordance with some examples, the respective operation is transitioning the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) from a locked state to an unlocked state. In some examples, transitioning the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) to an unlocked state includes enabling the display (e.g.,  2802 ), the one or more biometric sensors (e.g.,  2803 ), and/or the microphone of the electronic device. 
     In accordance with some examples, the respective operation is enabling the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) to participate in a transaction (e.g., financial transaction such as a payment for a good or service). 
     In accordance with some examples, while using the one or more biometric sensors (e.g.,  2803 ) to determine whether biometric authentication criteria are met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) displays, on the display (e.g.,  2802 ), an indication (e.g., a small indicator is displayed at the top, bottom, side, or in a corner) that biometric authentication is being performed. In some examples, no indicator is displayed during biometric authentication. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  2800 ) forgoes displaying an indication that biometric authentication is being performed, while determining, using the one or more biometric sensors (e.g.,  2803 ), whether biometric authentication criteria are met. In some examples, a first visual indication (e.g.,  2822 ) is displayed if the biometric authentication criteria are not met in response to the first request (e.g.,  2806 ) due to the one or more biometric sensors (e.g.,  2803 ) not detecting the presence of a biometric feature of the respective type. In some examples, a second visual indication (e.g.,  2832 ) (e.g., the same as or different from the first visual indication) is displayed if the biometric authentication criteria are not met in response to the first request (e.g.,  2806 ) due to the one or more biometric sensors (e.g.,  2803 ) detecting a biometric feature of the respective type that does not correspond to the authorized biometric feature. In some examples, a third visual indication (e.g.,  2852 ) is displayed if the biometric authentication criteria are met (e.g., a third visual indication that is different from the first visual indication and/or the second visual indication). 
     Note that details of the processes described above with respect to method  2900  (e.g.,  FIGS. 29A-29B ) are also applicable in an analogous manner to the methods described below and above. For example, method  2900  optionally includes one or more of the characteristics of the various methods described above with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  2000 ,  2200 ,  2500 ,  2700 ,  3100 ,  3300 , and  3500 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to method  2900 . As a further example, the authentication caching of method  3100  can be based on successful authentication performed in accordance with a re-performed biometric authentication as described with respect to method  2900 . For brevity, these details are not repeated below. 
       FIGS. 30A-30AL  illustrate exemplary user interfaces for cached biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary examples of the user interfaces illustrated in  FIGS. 30A-30AL  are used to illustrate the processes described below, including the processes in  FIGS. 31A-31B . 
       FIG. 30A  illustrates electronic device  3000  (e.g., portable multifunction device  100 , device  300 , device  500 , or device  1700 ). In the exemplary examples illustrated in  FIGS. 30A-30AL , electronic device  3000  is a smartphone. In other examples, electronic device  3000  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  3000  includes display  3002 , one or more input devices (e.g., touchscreen of display  3002 , button  3004 , and a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In  FIG. 30A , the electronic device includes biometric sensor  3003 . In some examples, the biometric sensor is one or more biometric sensors that can include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, biometric sensor  3003  is biometric sensor  703 . In some examples, the one or more biometric sensors include one or more fingerprint sensors (e.g., a fingerprint sensor integrated into a button). In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 30A , electronic device  3000  displays, on display  3002 , user interface  3006  of an application. The application is a mobile browser application, and the interface corresponds to a website (online.com). In some examples, the website online.com is the root domain of the online.com domain. Electronic device  3000  detects tap gesture  3008  on log-in affordance  3010 . Electronic device  3000  identifies tap gesture  3008  as a request to load log-in user interface  3012  (shown in  FIG. 30B ). User interface  3012  is the webpage id.online.com. In some examples, id.online.com is a subdomain of online.com domain that requires successful authentication before access is granted to restricted content. Electronic device  3000  also identifies tap gesture  3008  as a request to autofill fillable fields, username field  3014  and password field  3016 , in log-in user interface  3012 . The request to autofill requires biometric authentication in order to proceed with autofilling the fillable fields. In some examples, the request also includes a request to automatically log-in the user such that the user does not need to tap a submit affordance (e.g.,  3030 ,  3046 ) in order to submit credentials and log-in. 
     In  FIG. 30B , in response to tap gesture  3008  (e.g., the request to autofill Tillable fields), electronic device  3000  uses biometric sensor  3003  to determine whether certain biometric authentication criteria have been met. Electronic device  3000  captures and processes (e.g., analyzes) the biometric data from biometric sensor  3003  to determine, based on the biometric data, whether the biometric feature (or a portion thereof) satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template). Biometric sensor  3003  is contactless such that the sensor is configured to perform biometric authentication without physical input from the user (e.g., without any additional gestures after tap gesture  3008 ). As a result, electronic device  3000  initiates biometric authentication using biometric sensor  3003  without needing to receive an explicit request from a user to initiate biometric authentication. 
     Performing biometric authentication includes displaying biometric authentication interface  3018  having biometric authentication glyph  3020 . Biometric authentication glyph  3020  is a simulation of a representation of a biometric feature (e.g., a face). As shown in  FIG. 30B , biometric authentication interface  3018  is overlaid on at least a portion of log-in user interface  3012 . Biometric authentication interface  3018 , optionally, is an operating system level interface (e.g., an interface generated by an operating system of the device), and log-in user interface  3012  is an application-level interface (e.g., a user interface generated by a third-party application that is separate from the operating system of the device). 
     In  FIG. 30C , electronic device  3000  displays a portion of a biometric authentication animation including biometric authentication glyph  3022 , which serves as a portion of the animation during which biometric sensor  3003  obtains biometric data. In some examples, the animation of which glyphs  3020  and  3022  are a part indicates that the electronic device is attempting to identify a biometric feature of a particular type (e.g., identify a face). Once electronic device  3000  has obtained biometric data (e.g., obtained sufficient biometric data), electronic device  3000  transitions to displaying biometric authentication glyph  3024 , as shown in  FIG. 30D . Electronic device  3000  displays biometric authentication glyph  3024  to indicate that the biometric data is being processed. In some examples, biometric authentication glyph  3024  includes a plurality of rings, which rotate spherically, for instance, while displayed. 
     In  FIG. 30E , a determination is made that biometric authentication is successful. As a result, electronic device  3000  displays successful biometric authentication glyph  3026  indicating that biometric authentication was successful. 
     In  FIG. 30F , since biometric authentication was successful, electronic device  3000  autofills username field  3014  and password field  3016  with credential information (e.g., a username and password that enables a user to successfully log-in to an account). Electronic device  3000  autofills the fields while the device is in an unlocked state. In some examples, a determination is made that biometric authentication failed (e.g., biometric authentication criteria have not been met). As a result, in those examples, electronic device  3000  forgoes autofilling the one or more fillable fields (e.g., username field  3014  and password field  3016 ). 
     In  FIG. 30G , electronic device  3000  detects tap gesture  3028  on submit affordance  3030 . In response to detecting tap gesture  3028 , electronic device  3000  submits the credential information in username field  3014  and password field  3016  for user authentication. Upon successful user authentication, electronic device  3000  provides access to restricted content (e.g., content that can only be seen once a user has logged in) in account user interface  3032  of  FIG. 30H . 
     In  FIG. 30I , electronic device  3000  detects tap gesture  3034  on shop affordance  3036 . Electronic device  3000  identifies tap gesture  3034  as a request to load log-in user interface  3038  (shown in  FIG. 30J ). User interface  3038  is the webpage shop.online.com. In some examples, shop.online.com is a subdomain of online.com domain that requires successful authentication before access is granted to restricted content. In some examples, such as the example of  FIG. 30J , the subdomain shop.online.com requires separate authentication than that required by one or more other subdomains of the online.com domain, such as the subdomain id.online.com, discussed with respect to  FIG. 30B-30I . Electronic device  3000  also identifies tap gesture  3034  as a request to autofill one or more fillable fields (e.g., username field  3040  and password field  3042 ) in log-in user interface  3038 . As described earlier, in some examples, the request also includes a request to automatically log-in the user such that the user does not need to tap a submit affordance (e.g.,  3030 ,  3046 ) in order to submit credentials and log-in. 
     In response to the request to autofill the fillable fields, a determination is made that cached authentication is available for use from the successful authentication that occurred in  FIG. 30E . As a result, electronic device  3000  forgoes re-performing biometric authentication and proceeds to autofill username field  3040  and password field  3042 , as shown in  FIG. 30J . Electronic device  3000  autofills the fields regardless of whether biometric sensor  3003  detects a biometric feature (e.g., a face or a finger). In  FIG. 30K , electronic device  3000  detects tap gesture  3044  on submit affordance  3046 . In response to detecting tap gesture  3044 , electronic device  3000  submits the credential information in username field  3040  and password field  3042  for user authentication. Upon successful user authentication, electronic device  3000  provides access to restricted content (e.g., content that can only be seen once a user has logged in) in shop user interface  3048  of  FIG. 30L . 
     Alternatively, in response to the request to autofill the fillable fields, a determination is made that cached authentication is not available for use.  FIGS. 30N-30V , as described below, illustrate various examples that cause cached authentication to not be available for use by electronic device  3000 .  FIGS. 30W-Y , as described below, depict that biometric authentication must be performed when cached authentication is not available for use. 
     In  FIG. 30M , electronic device  3000  displays shop user interface  3048  and detects tap gesture  3050  on link affordance  3052 . In response to detecting tap gesture  3050 , electronic device  3000  displays account user interface  3032 , as shown in  FIG. 30N . 
       FIGS. 30N-30O  depict one example that causes cached authentication to not be available for use by electronic device  3000 . In  FIG. 30N , electronic device  3000  detects input (e.g., single press) by finger  3054  at home button  3056 . In response to detecting the input, electronic device  3000  displays home screen  3058 , as shown in  FIG. 30O , and causes the application with account user interface  3032  to enter an inactive state (e.g., suspended state, hibernated state, background state, and/or non-active state). If the application has been in an inactive state for more than a threshold amount of time (e.g., two minutes and forty seconds) between when the fillable fields in log-in user interface  3012  (e.g.,  FIG. 30F ) are autofilled and the request to autofill the fillable fields in log-in user interface  3038  (e.g.,  FIG. 30J ) is received, cached authentication is not available for use by electronic device  3000 . 
       FIGS. 30P-30T  depict one example that causes cached authentication to not be available for use by electronic device  3000 . In  FIG. 30P , electronic device  3000  detects input (e.g., double press) by finger  3054  at home button  3056 . In response to detecting the input, electronic device  3000  displays recently used apps view  3060 , as shown in  FIG. 30Q . In  FIGS. 30R-30S , electronic device  3000  detects swipe gesture  3062 , which causes the application with account user interface  3032  to close (e.g., terminate). As a result, electronic device  3000  displays recently used apps view  3060 , which no longer includes the application with account user interface  3032 , as illustrated by  FIG. 30T . Once the application has been closed between when the fillable fields in log-in user interface  3012  (e.g.,  FIG. 30F ) are autofilled and the request to autofill the fillable fields in log-in user interface  3038  (e.g.,  FIG. 30J ) is received, cached authentication is not available for use by electronic device  3000 . 
       FIGS. 30U-30V  depict one example that causes cached authentication to not be available for use by electronic device  3000 . In  FIG. 30U , electronic device  3000  detects input (e.g., single press) by finger  3064  at button  3004 . In response to detecting the input, electronic device  3000  transitions the device from an unlocked state to a locked state. Transitioning the device to a locked state includes deactivating (e.g., disabling) display  3002 , the one or more biometric sensors  3003 , and/or the microphone of electronic device  3000 . In  FIG. 30V , electronic device  3000  is in a locked state and does not display anything on display  3002 . Once electronic device  3000  transitions to a locked state between when the fillable fields in log-in user interface  3012  (e.g.,  FIG. 30F ) are autofilled and the request to autofill the fillable fields in log-in user interface  3038  (e.g.,  FIG. 30J ) is received, cached authentication is not available for use by electronic device  3000 . 
     In  FIG. 30W , electronic device  3000  displays account user interface  3032 , after cached authentication is no longer available (e.g., after one or more of the sequence of events discussed with respect to  FIG. 30N-30O, 30P-30T , or  30 U- 30 V). Electronic device  3000  detects tap gesture  3034  on shop affordance  3036 . Electronic device  3000  identifies tap gesture  3034  as a request to load log-in user interface  3038  (shown in  FIG. 30X ). Electronic device  3000  also identifies tap gesture  3034  as a request to autofill one or more fillable fields (e.g., username field  3040  and password field  3042 ) in log-in user interface  3038 . As described earlier, in some examples, the request also includes a request to automatically log-in the user such that the user does not need to tap a submit affordance to submit credentials and log-in. 
     In response to the request to autofill the one or more fillable fields, a determination is made that cached authentication is not available for use by electronic device  3000 . In  FIG. 30Y , electronic device  3000  re-performs biometric authentication using the one or more biometric sensors  3003 . Biometric authentication occurs automatically in response receiving the request to autofill the fillable fields such that intermediate input from the user is not needed to initiate biometric authentication. If biometric authentication is successful (e.g., biometric authentication criteria are met), electronic device autofills the fillable fields. If biometric authentication is not successful (e.g., biometric authentication criteria are not met), electronic device  3000  forgoes autofilling the fillable fields. 
     In  FIG. 30Z , a user is not logged-in and is presented with a user interface similar to  FIG. 30A . Electronic device  3000  displays, on display  3002 , user interface  3006  of the application. Electronic device  3000  detects tap gesture  3008  on log-in affordance  3010 . Electronic device  3000  identifies tap gesture  3008  as a request to load log-in user interface  3012  (shown in  FIG. 30AA ). Electronic device  3000  also identifies tap gesture  3008  as a request to autofill one or more fillable fields (e.g., username field  3014  and password field  3016 ) in log-in user interface  3012 . The request to autofill requires biometric authentication in order to proceed with autofilling the fillable fields. As described earlier, in some examples, the request also includes a request to automatically log-in the user such that the user does not need to tap a submit affordance to submit credentials and log-in. 
     In  FIG. 30AA , in response to the request to autofill the fillable fields, electronic device  3000  uses the biometric sensor  3003  to determine whether certain biometric authentication criteria have been met. Biometric sensor  3003  is contactless such that the sensor is configured to perform biometric authentication without physical input from the user. As a result, electronic device  3000  initiates biometric authentication using biometric sensor  3003  without needing to receive an explicit request from a user to initiate biometric authentication. Biometric authentication is not successful (e.g., biometric authentication criteria are not met). As a result, electronic device  3000  displays failure interface  3066  in  FIG. 30AB  upon failed biometric authentication, as described with respect to  FIG. 17M . Failure interface  3066  can be displayed when a user has not reached the maximum number of failed biometric authentication attempts. 
     In  FIG. 30AC , electronic device  3000  detects tap gesture  3068  on cancel affordance  3070 . In response to detecting tap gesture  3068 , electronic device  3000  displays log-in user interface  3012  (shown in  FIG. 30AD ). In  FIG. 30AD , in response to detecting selection of username field  3014 , electronic device  3000  displays cursor  3072  in username field  3014  and also displays virtual keyboard  3074 . Electronic device  3000  receives input entering one or more characters corresponding to credential information in username field  3014  and password field  3016 . In  FIG. 30AE , electronic device  3000  detects tap gesture  3028  on submit affordance  3030 . As a result, electronic device  3000  submits the credential information in username field  3014  and password field  3016  for user authentication. Upon successful user authentication, electronic device  3000  provides access to restricted content (e.g., content that can only be seen once a user has logged in) in account user interface  3032  of  FIG. 30AF . 
     In  FIG. 30AG , electronic device  3000  detects tap gesture  3034  on shop affordance  3036 . Electronic device  3000  identifies tap gesture  3034  as a request to load log-in user interface  3038  (shown in  FIG. 30AH ). Electronic device  3000  also identifies tap gesture  3034  as a request to autofill one or more fillable fields (e.g., username field  3040  and password field  3042 ) in log-in user interface  3038 . As described earlier, in some examples, the request also includes a request to automatically log-in the user such that the user does not need to tap a submit affordance to submit credentials and log-in. 
     In response to the request to autofill the one or more fillable fields, a determination is made that cached authentication is not available for use by electronic device  3000 . In  FIG. 30AH , electronic device  3000  performs biometric authentication using biometric sensor  3003 . Biometric authentication occurs automatically in response receiving the request to autofill the fillable fields such that intermediate input from the user is not needed to initiate biometric authentication. 
     In  FIG. 30AI , a determination is made that biometric authentication is successful (e.g., biometric authentication criteria are met). As a result, electronic device  3000  displays biometric authentication interface  3018  with successful biometric authentication glyph  3026  indicating that biometric authentication was successful. Upon successful biometric authentication, electronic device  3000  autofills username field  3040  and password field  3042  with credential information, as shown in  FIG. 30AJ . 
     In  FIG. 30AJ , electronic device  3000  detects tap gesture  3044  on submit affordance  3046 . In response to detecting tap gesture  3044 , electronic device  3000  submits the credential information in username field  3040  and password field  3042  for user authentication. Upon successful user authentication, electronic device  3000  provides access to restricted content (e.g., content that can only be seen once a user has logged in) in shop user interface  3048  of  FIG. 30AK . 
     In some examples, electronic device  3000  displays a biometric authentication interface with a biometric authentication glyph, which indicate that biometric authentication is being performed. In some examples, the displayed biometric authentication interface is approximately centered along a horizontal and/or vertical axis such as in  FIGS. 30B-30E . In other examples, electronic device  3000  displays the biometric authentication interface at the top, bottom, side, or in a corner of display  3002 . For example, electronic device  3000  displays biometric authentication interface  3076  near the top of display  3002 , as shown in  FIG. 30AL . In some examples, electronic device  3000  does not display the biometric authentication interface while biometric authentication is being performed. 
       FIGS. 31A-31B  are a flow diagram illustrating a method for determining if biometric re-authentication is required or if cached authentication is available for use using an electronic device in accordance with some examples. Method  3100  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) with one or more biometric sensors (e.g.,  3003 ) (e.g., a fingerprint sensor, a contactless biometric sensor (e.g., a biometric sensor that does not require physical contact, such as a thermal or optical facial recognition sensor), an iris scanner). In some examples, the one or more biometric sensors (e.g.,  3003 ) include one or more cameras. The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) optionally includes a display (e.g.,  3002 ). In some examples, the display (e.g.,  3002 ) is a touch-sensitive display. In some examples, the display (e.g.,  3002 ) is not a touch sensitive display. 
     Some operations in method  3100  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. As described below, method  3100  provides an intuitive way for determining if biometric re-authentication is required or if cached authentication is available for use. The method reduces the cognitive burden on a user for authenticating on an electronic device, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to authenticate faster and more efficiently conserves power and increases the time between battery charges. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) receives ( 3102 ) a first request (e.g.,  3008 ) (e.g., select password to autofill, unlock device, make payment) to perform a first operation that requires authentication. 
     In response ( 3104 ) to receiving the first request (e.g.,  3008 ) to perform the first operation, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) proceeds to blocks  3106 - 3110 . 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) uses ( 3106 ) the one or more biometric sensors (e.g.,  3003 ) to determine whether first biometric authentication criteria are met. The first biometric authentication criteria include a requirement that a biometric feature of a respective type (e.g., a face or fingerprint) that is authorized to perform the first operation is detected by the biometric sensors (e.g.,  3003 ). 
     In accordance with a determination that the first biometric authentication criteria are met (e.g., at least a portion of a biometric feature, determined based on data obtained from the one or more biometric sensors (e.g.,  3003 ) that correspond to the biometric feature, satisfies biometric authentication criteria (e.g., a face that was detected is consistent with an authorized face)), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) performs ( 3108 ) the first operation. Performing the first operation upon a request and successful authentication provides the user with capability to perform the first operation without requiring further inputs (beyond the request). Performing an operation when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with a determination that the biometric authentication criteria are not met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) forgoes ( 3110 ) performing the first operation. Forgoing (or performing) the respective operation based on not meeting biometric authentication criteria provides security and can prevent unauthorized users from initiating sensitive operations. Providing improved security enhances the operability of the device and makes the user-device interface more efficient (e.g., by restricting unauthorized access) which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     After performing the first operation, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) receives ( 3112 ) a second request (e.g.,  3034 ) (e.g., select password to autofill, unlock device, make a payment) to perform a second operation (e.g., an operation that is the same or different than the first operation) that requires authentication. 
     In response ( 3114 ) to receiving the second request (e.g.,  3034 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) proceeds to blocks  3116 - 3118 . 
     In accordance with a determination that re-authentication criteria have been met (e.g., cached authentication is not permitted for the second operation or cached authentication is not available for use), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) uses ( 3116 ) the one or more biometric sensors (e.g.,  3003 ) to determine whether second biometric authentication criteria are met. The second biometric authentication criteria include a requirement that a biometric feature of a respective type (e.g., a face or fingerprint) that is authorized to perform the second operation is detected by the biometric sensors (e.g.,  3003 ). In some examples, the first and second biometric authentication criteria are the same. In some examples, the first and second biometric authentication criteria are different. Performing biometric authentication when cached authentication is not available provides security and can prevent unauthorized users from initiating sensitive operations. Providing improved security enhances the operability of the device and makes the user-device interface more efficient (e.g., by restricting unauthorized access) which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     In accordance with a determination that the re-authentication criteria have not been met (e.g., cached authentication is available for use), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) performs ( 3118 ) the second operation without performing biometric authentication and forgoing using the one or more biometric sensors (e.g.,  3003 ) to determine whether the second biometric authentication criteria are met. Performing the second operation upon a request without requiring re-authentication provides the user with a capability to perform an operation without requiring further inputs (beyond the request). Performing an operation when a set of conditions has been met without requiring further user input or re-authentication enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, the first operation and the second operation occur while the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) is in an unlocked state. In some examples, using the one or more biometric sensors (e.g.,  3003 ) to determine whether second biometric authentication criteria are met occurs while the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) is in an unlocked state. Performing biometric authentication while the device is an unlocked state enables the device to provide feedback by displaying an indication of the progress of the biometric authentication. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, in response to receiving the second request (e.g.,  3034 ) and in accordance with a determination that the second biometric authentication criteria are not met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) forgoes performing the second operation. 
     In accordance with some examples, performing the second operation occurs regardless of whether a biometric feature of the respective type that is authorized to perform the second operation is detected by the biometric sensors (e.g.,  3003 ) in response to receiving the second request (e.g.,  3034 ). 
     In accordance with some examples, the first operation is logging on (e.g.,  3028 ) a first web domain, and the second operation is logging on (e.g.,  3044 ) a second web domain corresponding to the first web domain. In some examples, the second web domain is the same as the first web domain. In some examples, the second web domain is a subdomain of the first web domain. 
     In accordance with some examples, the re-authentication criteria include a requirement that the device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) has been in a locked state between when the first operation is performed and when the second request (e.g.,  3034 ) is received (e.g., cached authentication is not available for use) (e.g., re-authentication criteria are not met and biometric authentication is not required again when the device has remained in an unlocked state between when the first operation is performed and when the second request is received). 
     In accordance with some examples, the first operation is performed in an application, and the re-authentication criteria includes a requirement that the application has been closed (e.g., terminated) between when the first operation is performed and when the second request (e.g.,  3034 ) is received (e.g., cached authentication is not available for use) (e.g., re-authentication criteria are not met and biometric authentication is not required again when the application has remained open between when the first operation is performed and when the second request is received). 
     In accordance with some examples, the re-authentication criteria includes a requirement that the application has been in an inactive state (e.g., suspended state, hibernated state, background state, non-active state) for more than a threshold amount of time (e.g., 2 minutes and 40 seconds) between when the first operation is performed and when the second request (e.g.,  3034 ) is received (e.g., cached authentication is not available for use) (e.g., re-authentication criteria are not met and biometric authentication is not required again when the application has remained in an active state between when the first operation is performed and when the second request is received). 
     In accordance with some examples, using the one or more biometric sensors (e.g.,  3003 ) to determine whether the second biometric authentication criteria are met occurs automatically (e.g., without the need for an intermediate input from the user) in response to receiving the second request (e.g.,  3034 ) to perform the second operation that requires authentication. 
     In accordance with some examples, the one or more biometric sensors (e.g.,  3003 ) are contactless biometric sensors (e.g., infrared camera, visible light camera, or combinations thereof) configured to perform biometric authentication without physical contact from the user (e.g., the one or more biometric sensors (e.g.,  3003 ) can perform biometric authentication without a physical input (e.g., a touch or button press) from the user). 
     In accordance with some examples, while using the one or more biometric sensors (e.g.,  3003 ) to determine whether first or second biometric authentication criteria are met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) displays, on the display (e.g.,  3002 ), an indication (e.g.,  3076 ) (e.g., a small indicator is displayed at the top, bottom, side, or in a corner) that biometric authentication is being performed. Displaying a small indicator away from the center of the display provides the user an indication of the progress of the biometric authentication without obstructing or cluttering the display and diverting the user&#39;s focus, thereby providing improved visual feedback during the authentication. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3000 ) forgoes displaying an indication that biometric authentication is being performed, while determining, using the one or more biometric sensors (e.g.,  3003 ), whether biometric authentication criteria are met. 
     Note that details of the processes described above with respect to method  3100  (e.g.,  FIGS. 31A-31B ) are also applicable in an analogous manner to the methods described below and above. For example, method  3100  optionally includes one or more of the characteristics of the various methods described above with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  2000 ,  2200 ,  2500 ,  2700 ,  2900 ,  3300 , and  3500 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to method  3100 . As a further example, the visibility criteria of method  3300  can be used in conjunction with method  3100  to control when biometric authentication should be performed (or re-performed). For brevity, these details are not repeated below. 
       FIGS. 32A-32W  illustrate exemplary user interfaces for autofilling Tillable fields based on visibility criteria, in accordance with some examples. As described in greater detail below, the exemplary examples of the user interfaces illustrated in  FIGS. 32A-32W  are used to illustrate the processes described below, including the processes in  FIG. 33 . 
       FIG. 32A  illustrates electronic device  3200  (e.g., portable multifunction device  100 , device  300 , or device  500 ). In the exemplary examples illustrated in  FIGS. 32A-32W , electronic device  3200  is a smartphone. In other examples, electronic device  3200  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  3200  includes display  3202 , one or more input devices (e.g., touchscreen of display  3202  and a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In  FIG. 32A , the electronic device includes biometric sensor  3203 . In some examples, the biometric sensor is one or more biometric sensors that can include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, biometric sensor  3203  is biometric sensor  703 . In some examples, the one or more biometric sensors include one or more fingerprint sensors (e.g., a fingerprint sensor integrated into a button). In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In  FIG. 32A , electronic device  3200  displays, on display  3202 , user interface  3204  of an application. The application is a mobile browser application, and the interface corresponds to a website (airline.com). In  FIGS. 32B-32D , electronic device  3200  does not initiate biometric authentication because a log-in user interface has not met certain visibility criteria. For example, the visibility criteria can include whether a threshold amount of one or more fillable fields (e.g., corresponding to credential information) is displayed within a visible area of a user interface. 
     In  FIGS. 32B-32C , electronic device  3200  detects scroll gesture  3206  in an upward motion. In response to detecting scroll gesture  3206 , electronic device  3200  causes user interface  3204  to scroll down. In  FIG. 32D , subsequent to scroll gesture  3206 , electronic device  3200  displays scrolled user interface  3208 . Electronic device  3200  still has not initiated biometric authentication due to a determination that the visibility criteria have not been met. 
     In  FIG. 32E , electronic device  3200  detects tap gesture  3210  on hidden menu affordance  3212 . In response to detecting tap gesture  3210 , electronic device  3200  displays hidden menu  3214 , which includes one or more fillable fields (e.g., username field  3216  and password field  3218 ), as shown in  FIG. 32F . Electronic device  3200  displays hidden menu  3214 , which is overlaid on scrolled user interface  3208  such that a covered portion of scrolled user interface  3208  is no longer displayed. A determination is made as to whether the fillable fields meet certain visibility criteria. 
     If it is determined that the fillable fields meet certain visibility criteria, electronic device  3200  receives a request to autofill the fillable fields in hidden menu  3214  with credential information (e.g., a username and password that enables a user to successfully log-in to an account). The request to autofill requires biometric authentication in order to proceed with autofilling the fillable fields. In some examples, the request also includes a request to automatically log-in the user such that the user does not need to tap a submit affordance (e.g., submit affordance  3232  in  FIG. 32L ) in order to submit credentials and log-in. 
     In  FIG. 32G , upon a determination that the one or more fillable fields do meet certain visibility criteria, electronic device  3200  uses biometric sensor  3203  to determine whether certain biometric authentication criteria have been met. Electronic device  3200  captures and processes (e.g., analyzes) the biometric data from biometric sensor  3203  to determine, based on the biometric data, whether the biometric feature (or a portion thereof) satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template). Biometric authentication occurs automatically once the determination is made that the fillable fields meet the visibility criteria. Biometric sensor  3203  is contactless such that the sensor is configured to perform biometric authentication without physical contact from the user. As a result, electronic device  3200  initiates biometric authentication using biometric sensor  3203  without receiving an explicit request from a user to initiate biometric authentication. In some examples, initiating biometric authentication includes detecting a contact with one or more fingerprint sensors, and determining whether the contact meets certain fingerprint authentication criteria (e.g., determines whether a fingerprint is consistent with a registered fingerprint as discussed above with respect to secure element  115 ; determines whether a fingerprint matches stored information as discussed above with respect to methods  1600 ,  1800 ,  2200 , and  FIGS. 17O and 21 ). In some examples, determining whether a fingerprint is consistent with a registered fingerprint is performed according to one or more of the methods discussed in U.S. Pat. App. Pub. No. 2015/0146945 (e.g., at paragraphs [0119]-[0121]). U.S. Pat. App. Pub. No. 2015/0146945 is hereby incorporated by reference, specifically with respect to its disclosure of methods of determining whether a fingerprint is consistent with a registered fingerprint. 
     Alternatively, a determination can be made that the one or more fillable fields do not meet certain visibility criteria. If the fillable fields do not meet the visibility criteria, electronic device  3200  forgoes initiating biometric authentication. 
     Performing biometric authentication includes displaying biometric authentication interface  3220  having biometric authentication glyph  3222 . Biometric authentication glyph  3222  is a simulation of a representation of a biometric feature (e.g., a face). As shown in  FIG. 32G , biometric authentication interface  3220  is overlaid on at least a portion of hidden menu  3214 . Biometric authentication interface  3220 , optionally, is an operating system level interface (e.g., an interface generated by an operating system of the device), and hidden menu  3214  is an application-level interface (e.g., a user interface generated by a third-party application that is separate from the operating system of the device). In some examples, the displayed biometric authentication interface is approximately centered along a horizontal and/or vertical axis such as in  FIGS. 32G-32J . In some examples, electronic device  3200  displays the biometric authentication interface at the top, bottom, side, or in a corner of display  3202 . For example, electronic device  3200  displays the biometric authentication interface near the top of display  3202 , such as in, for example,  FIG. 30AL . In some examples, electronic device  3200  does not display the biometric authentication interface while biometric authentication is being performed. 
     In  FIG. 32H , electronic device  3200  displays a portion of a biometric authentication animation including biometric authentication glyph  3224 , which serves as a portion of the animation during which biometric sensor  3203  obtains biometric data. Once electronic device  3200  has obtained biometric data (e.g., obtained sufficient biometric data), electronic device  3200  transitions to displaying biometric authentication glyph  3226 , as shown in  FIG. 32I . Electronic device  3200  displays biometric authentication glyph  3226  to indicate that the biometric data is being processed. In some examples, biometric authentication glyph  3226  includes a plurality of rings, which rotate spherically, for instance, while displayed. 
     In  FIG. 32J , a determination is made that biometric authentication is successful. As a result, electronic device  3200  displays successful biometric authentication glyph  3228  indicating that biometric authentication was successful. 
     In  FIG. 32K , since biometric authentication was successful, electronic device  3200  autofills the one or more fillable fields (e.g., username field  3216  and password field  3218 ) with credential information (e.g., log-in information such as a username and password that enables a user to successfully log-in to an account). In some examples, electronic device  3200  autofills the fillable fields with credit card information (e.g., information associated with a payment account information). 
     Alternatively, a determination can be made that biometric authentication criteria have not been met. If biometric authentication failed, electronic device  3200  forgoes autofilling the one or more fillable fields with credential information (e.g., log-in information or credit card information). Forgoing autofilling the one or more fillable fields optionally includes displaying a failure interface such as failure interface  2854  in  FIG. 28X  or failure interface  2856  in  FIG. 28Y . 
     In  FIG. 32L , electronic device detects tap gesture  3230  on submit affordance  3232 . In response to detecting tap gesture  3230 , electronic device  3200  submits the credential information in username field  3216  and password field  3218  for user authentication. Upon successful authentication, electronic device  3200  provides access to restricted content (e.g., content that can only be seen once a user has logged in) in member user interface  3234  of  FIG. 32M . 
       FIGS. 32N-32W  illustrate various scenarios in which certain visibility criteria initially were not met, and then subsequent to user input, the visibility criteria were met. 
     In  FIG. 32N , electronic device  3200  displays, on display  3202 , user interface  3236  of an application. The application is a mobile browser application, and the interface corresponds to a website (restaurant.com). User interface  3236  includes one or more fillable fields (e.g., username field  3238  and password field  3240 ). The fillable fields are displayed within the visible area of user interface  3236  at a size that is below a threshold size (e.g., a threshold size that must be met or exceeded in order to meet the certain visibility criteria). 
     In  FIG. 32O , while displaying user interface  3236 , electronic device  3200  detects zoom gesture  3242 . In response to detecting zoom gesture  3242 , electronic device  3200  displays enlarged user interface  3244  as shown in  FIG. 32P . Enlarged user interface  3244  includes enlarged username field  3246  and enlarged password field  3248 . A determination is made that zoom gesture  3242  did not cause the fillable fields to meet certain visibility criteria. For example, the fillable fields are still displayed within the visible area of enlarged user interface  3244  at a size that is below the threshold size. Upon the determination that the visibility criteria are still not met, electronic device  3200  forgoes initiating biometric authentication. 
     In  FIG. 32Q , while displaying enlarged user interface  3244 , electronic device  3200  detects zoom gesture  3250 . In response to detecting zoom gesture  3250 , electronic device  3200  displays enlarged user interface  3252 , as shown in  FIG. 32R . Enlarged user interface  3252  includes enlarged username field  3254  and enlarged password field  3256 . A determination is made that zoom gesture  3250  caused the fillable fields to meet the visibility criteria. For example, the fillable fields are now displayed within the visible area of enlarged user interface  3252  at a size that is at or above the threshold size. Upon the determination that the visibility criteria are met, electronic device  3200  initiates biometric authentication, and displays biometric authentication interface  3220  with biometric authentication glyph  3222 , as described with respect to  FIG. 32G . 
     In  FIG. 32S , electronic device  3200  displays, on display  3202 , user interface  3258  of an application. The application is a mobile browser application, and the interface corresponds to a website (newsfeed.com). User interface  3258  is a user interface region that corresponds to a portion of an electronic document (e.g., an HTML document). The electronic document includes one or more fillable fields (e.g., username field  3268  and password field  3270  in  FIG. 32W ) that are outside of the visible area of user interface  3258 . 
     In  FIG. 32T , while displaying user interface  3258 , electronic device  3200  detects scroll gesture  3260  in an upward motion. In response to detecting scroll gesture  3260 , electronic device  3200  causes user interface  3258  to scroll down. In  FIG. 32U , subsequent to scroll gesture  3260 , electronic device  3200  displays scrolled user interface  3262 , which includes displaying a portion of the one or more fillable fields (e.g., username field  3268 ). A determination is made that scroll gesture  3260  did not cause the one or more fillable fields to meet certain visibility criteria. For example, the visibility criteria includes whether a threshold amount of the one or more fillable fields is displayed within a visible area of scrolled user interface  3262 . Upon the determination that the visibility criteria are still not met, electronic device  3200  forgoes initiating biometric authentication. 
     In  FIG. 32V , while displaying scrolled user interface  3262 , electronic device  3200  detects scroll gesture  3264 . In response to detecting scroll gesture  3264 , electronic device  3200  causes scrolled user interface  3262  to further scroll down. In  FIG. 32W , subsequent to scroll gesture  3264 , electronic device  3200  displays scrolled user interface  3266 , which includes displaying the one or more fillable fields (e.g., username field  3268  and password field  3270 ). A determination is made that scroll gesture  3264  caused the fillable fields to meet the visibility criteria. For example, a threshold amount of the one or more fillable fields is now displayed within a visible area of scrolled user interface  3262 . Upon the determination that the visibility criteria are met, electronic device  3200  initiates biometric authentication, and displays biometric authentication interface  3220  with biometric authentication glyph  3222 , as described with respect to  FIG. 32G . 
       FIG. 33  is a flow diagram illustrating a method for determining when to perform an authentication operation using an electronic device in accordance with some examples. Method  3300  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) with a display (e.g.,  3202 ). In some examples, the display (e.g.,  3202 ) is a touch-sensitive display. In some examples, the display (e.g.,  3202 ) is not a touch sensitive display. 
     Some operations in method  3300  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. As described below, method  3300  provides an intuitive way for determining when to perform an authentication operation. The method reduces the cognitive burden on a user for performing authentication operations thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to authenticate faster and more efficiently conserves power and increases the time between battery charges. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) receives ( 3302 ) a request (e.g.,  3210 ) to display a first portion (e.g.,  3214 ) of respective content (e.g.,  3208 ) (e.g., a request to load a webpage, scroll a webpage, zoom a webpage). 
     In response ( 3304 ) to the request (e.g.,  3210 ) to display the first portion (e.g.,  3214 ) of the respective content (e.g.,  3208 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) proceeds to blocks  3306 - 3310 . 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) displays ( 3306 ), on the display (e.g.,  3202 ), at least the first portion (e.g.,  3214 ) of the respective content (e.g.,  3208 ) (e.g., a region of an electronic document (e.g., an HTML document) having user-interactive elements). The respective content (e.g.,  3208 ) includes an element (e.g.,  3216 ,  3218 ) associated with an authentication operation (e.g., one or more fillable fields such as a credit card entry field, a log-in user interface element that optionally includes a username and password fields for logging in to a service). 
     In accordance with a determination that the element (e.g.,  3216 ,  3218 ) associated with the authentication operation meets visibility criteria (e.g., the element associated with the authentication operation is entirely outside of a visible area of the content, at least a threshold amount of the element associated with the authentication operation is outside of a visible area of the content, the element associated with the authentication operation is displayed within the visible area of the content at a size that is below a threshold size, and/or the element associated with the operation is contained in a portion of the content that is hidden from view such as being contained in a collapsed menu region or other hidden element) (e.g., at least a portion of the one or more fillable fields is displayed, the one or more fillable fields are fully displayed, and/or the one or more fillable fields are greater than a threshold size), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) initiates ( 3308 ) biometric authentication (e.g., as described with reference to  FIGS. 17G-17H ). In some examples, the region corresponds to a portion of an electronic document (e.g., an HTML document) and the one or more fillable fields are one or more elements of the electronic document having a property that causes the one or elements to be rendered in a visible state (e.g., an HTML element having a “style.display” property of “inline”). Initiating biometric authentication upon meeting visibility criteria provides the user with a capability to perform biometric authentication without requiring further inputs (beyond an input causing the visibility criteria to be met). Performing biometric authentication when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with a determination that the element (e.g.,  3216 ,  3218 ) associated with the authentication operation does not meet the visibility criteria (e.g., the element associated with the authentication operation is entirely displayed within a visible area of the content, at least a threshold amount of the element associated with the authentication operation is displayed within a visible area of the content, the element associated with the authentication operation is displayed within the visible area of the content at a size that is above the threshold size, and/or the element associated with the operation is contained in a portion of the content that is not otherwise hidden from view such as being contained in a collapsed menu region or other hidden element), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) forgoes ( 3310 ) initiating biometric authentication. Forgoing initiating biometric authentication based on not meeting visibility criteria prevents biometric authentication from occurring when a user did not intend for the device to initiate biometric authentication. Preventing unintentional biometric authentication enhances the operability of the device and makes the user-device interface more efficient (e.g., by restricting unauthorized access) which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     In accordance with some examples, the first portion (e.g.,  3214 ) of the respective content (e.g.,  3208 ) is displayed without displaying, on the display (e.g.,  3202 ), a second portion of the respective content. In some examples, second portion is displayed before displaying the first portion. 
     In accordance with some examples, biometric authentication occurs automatically (e.g., without an intermediate input being required to initiate biometric authentication) in accordance with the determination that the element (e.g.,  3216 ,  3218 ) associated with the authentication operation meets visibility criteria. 
     In accordance with some examples, while displaying the first portion (e.g.,  3236 ,  3258 ) of the respective content, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) detects an input (e.g.,  3242 ,  3250 ,  3260 ,  3264 ) (e.g., zoom, scroll, menu display). In response to detecting the input (e.g.,  3250 ,  3264 ) and in accordance with a determination that the input causes the element (e.g.,  3246 ,  3248 ,  3268 ,  3270 ) associated with the authentication operation to meet the visibility criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) initiates biometric authentication. Initiating biometric authentication in response to an input and upon meeting visibility criteria provides the user with a capability to perform biometric authentication without requiring further inputs (beyond the input causing the visibility criteria to be met). Performing biometric authentication when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In response to detecting the input (e.g.,  3242 ,  3260 ) and in accordance with a determination that the input does not cause the element (e.g.,  3238 ,  3240 ,  3268 ,  3270 ) associated with the authentication operation to meet the visibility criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) forgoes initiating biometric authentication. In some examples, an input (e.g.,  3210 ,  3242 ,  3250 ,  3260 ,  3264 ) (e.g., the selection of an affordance, a resizing request) affects the visibility characteristics of the element (e.g.,  3216 ,  3218 ,  3246 ,  3248 ,  3268 ,  3270 ) associated with the authentication operation, causing the element to transition from not meeting the visibility criteria to meeting the visibility criteria. Forgoing initiating biometric authentication based on not meeting visibility criteria prevents biometric authentication from occurring when a user did not intend for the device to initiate biometric authentication. Preventing unintentional biometric authentication enhances the operability of the device and makes the user-device interface more efficient (e.g., by restricting unauthorized access) which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     In accordance with some examples, the input (e.g.,  3242 ,  3250 ) is a request to perform a zoom operation, and the visibility criteria include a requirement that the element ( 3238 ,  3240 ,  3246 ,  3248 ,  3254 ,  3256 ) associated with the authentication operation has a size that is greater than a threshold size. 
     In accordance with some examples, the input ( 3260 ,  3264 ) is a request to perform a scroll operation, and the visibility criteria include a requirement that at least a predetermined amount of the element ( 3268 ,  3270 ) associated with the authentication operation is displayed on the display (e.g.,  3202 ). 
     In accordance with some examples, the input (e.g.,  3210 ) is a request to perform a hidden interface region display operation (e.g., a request to display a hidden menu or other hidden interface region), and the visibility criteria include a requirement that the element (e.g.,  3216 ,  3218 ) associated with the authentication operation is not designated for display in a hidden interface region. 
     In accordance with some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) further includes one or more biometric sensors (e.g.,  3203 ), and initiating biometric authentication includes initiating biometric authentication using the one or more biometric sensors (e.g.,  3203 ). 
     In accordance with some examples, the one or more biometric sensors (e.g.,  3203 ) includes one or more contactless biometric sensors (e.g., infrared camera, visible light camera, or combinations thereof) configured to perform biometric authentication without physical contact from the user (e.g., the one or more biometric sensors (e.g.,  3203 ) can perform biometric authentication without a physical input (e.g., a touch or button press) from the user). Initiating biometric authentication occurs without receiving an explicit request to initiate biometric authentication. 
     In accordance with some examples, the one or more biometric sensors (e.g.,  3203 ) include one or more facial recognition sensors. Initiating biometric authentication includes using the one or more facial recognition sensors to determine whether facial authentication criteria have been met (e.g., as described with respect to  FIGS. 23D-23F ). 
     In accordance with some examples, the one or more biometric sensors (e.g.,  3203 ) include one or more fingerprint sensors. Initiating biometric authentication includes: detecting a contact with the one or more fingerprint sensors and determining whether the contact meets fingerprint authentication criteria (e.g., fingerprint is consistent with a registered or authorized fingerprint). 
     In accordance with some examples, initiating biometric authentication includes displaying, on the display (e.g.,  3202 ), a progress indicator (e.g.,  3222 ,  3224 ,  3226 ,  3228 ) indicating the status of a biometric authentication process. In some examples, the progress indicator corresponds to a simulated progress indicator (e.g., a progress indicator that has some or all of the features of the progress indicator displayed surrounding the simulation of the biometric feature such as a plurality of progress elements that are distributed around a representation of the biometric feature of the user). In some examples, a small progress indicator is displayed at the top, bottom, side, or in a corner. Displaying a small indicator away from the center of the display provides the user an indication of the progress of the biometric authentication without obstructing or cluttering the display and diverting the user&#39;s focus, thereby providing improved visual feedback during the authentication. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. In some examples, no progress indicator is displayed during biometric authentication. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) forgoes displaying a progress indicator indicating the status of a biometric authentication process. 
     In accordance with some examples, the element associated with an authentication operation is a fillable field (e.g.,  3216 ,  3218 ,  3254 ,  3256 ,  3268 ,  3270 ) (e.g., a user name, password, credential, or payment information entry field). In response to initiating biometric authentication and in accordance with a determination that biometric authentication criteria have been met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) autofills the fillable field (e.g.,  3216 ,  3218 ,  3254 ,  3256 ,  3268 ,  3270 ) with credential information (e.g., populating a field with data stored by the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) or accessible to the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ), such as a user name, password, credit card information or other sensitive information). In response to initiating biometric authentication and in accordance with a determination that biometric authentication criteria have not been met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) forgoes autofilling the fillable field (e.g.,  3216 ,  3218 ,  3254 ,  3256 ,  3268 ,  3270 ) with credential information. 
     In accordance with some examples, in response to initiating biometric authentication and in accordance with a determination that biometric authentication criteria have been met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) provides access to restricted content (e.g., logging in to a webpage (e.g.,  3234 ), displaying a list of passwords associated with a user, displaying credit card information). In response to initiating biometric authentication and in accordance with a determination that biometric authentication criteria have not been met, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3200 ) forgoes providing access to restricted content. 
     In accordance with some examples, wherein the credential information includes log-in information (e.g., information required to login to an application, an account, or a website). 
     In accordance with some examples, wherein the credential information includes information associated with a payment account information (e.g., credit card, bank account, or payment service information). 
     Note that details of the processes described above with respect to method  3300  (e.g.,  FIG. 33 ) are also applicable in an analogous manner to the methods described below and above. For example, method  3300  optionally includes one or more of the characteristics of the various methods described above with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  2000 ,  2200 ,  2500 ,  2700 ,  2900 ,  3100 , and  3500 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to method  3300 . As a further example, the re-authentication criteria of method  3100  can be used in conjunction with method  3300  to control when biometric authentication should be performed (or re-performed). For brevity, these details are not repeated below. 
       FIGS. 34A-34N  illustrate exemplary user interfaces for automatic log-in using biometric authentication, in accordance with some examples. As described in greater detail below, the exemplary examples of the user interfaces illustrated in  FIGS. 34A-34N  are used to illustrate the processes described below, including the processes in  FIG. 35 . 
       FIG. 34A  illustrates electronic device  3400  (e.g., portable multifunction device  100 , device  300 , device  500 , or device  1700 ). In the exemplary examples illustrated in  FIGS. 34A-34N , electronic device  3400  is a smartphone. In other examples, electronic device  3400  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  3400  includes display  3402 , one or more input devices (e.g., touchscreen of display  3402  and a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In  FIG. 34A , the electronic device includes biometric sensor  3403 . In some examples, the biometric sensor is one or more biometric sensors that can include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, the biometric sensor is depth camera  175  of device  100  or a depth camera having one or more features and/or functions of a depth camera as described with respect to device  700  and certain examples of biometric sensor  703 . In some examples, biometric sensor  3403  is a depth camera that is used in conjunction with a visible light camera to determine a depthmap of different portions of subject captured by the visible light camera, as described above with respect to biometric sensor  703 . 
     Electronic device  3400 , as seen in  FIG. 34A , also includes a fingerprint sensor  3414  (e.g., a biometric sensor) that is integrated into a button. In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     In some examples, electronic device  3400  can share one or more features, elements, and/or components with devices  100 ,  300 ,  500 ,  700 ,  900 ,  1100 ,  1300 ,  1500 ,  1700 ,  1900 ,  2100 ,  2300 ,  2400 ,  2600 ,  2800 ,  3000 ,  3200 ,  3600 ,  3800 ,  4000 , and  4200  and each of those devices can share one or more features, elements, and/or components of another of those devices (e.g., device  700  can include a component of device  3200  and vice versa). For example, biometric sensor  3403  can be biometric sensor  903  or biometric sensor  1103  can be biometric sensor  1303 . For another example, button-integrated fingerprint sensor  3414  can be fingerprint sensor  1764 . For another example, display  3402  can be display  1302  or display  1502  can be display  2102 . 
     Prior to displaying log-in user interface  3404  in  FIG. 34A , electronic device  3400  detects a request to load log-in user interface  3404 . In response detecting the request, a determination is made as to whether biometric authentication using fingerprint sensor  3414  is available. Upon a determination that biometric authentication is available, electronic device  3400  displays log-in user interface  3404  with prompt  3406  (“SCAN FINGER TO LOGIN”) located in submit affordance  3420  (e.g., an affordance that, upon selection, submits credential information in one or more fillable fields (e.g., a username field or a password field)). Prompt  3406  indicates to the user that placing their finger on fingerprint sensor  3414  will cause credential information (e.g., a username and password that enables a user to successfully log-in to an account) to be submitted via username field  3408  and password field  3410 . Additionally, username field  3408  is prefilled with a default username (e.g., jj_appleseed@email.com), as shown in  FIG. 34A . In some examples, the username field is not prefilled with a username. 
     In  FIG. 34B , while displaying log-in user interface  3404 , electronic device  3400  detects finger  3412  using fingerprint sensor  3414 . In response to detecting finger  3412 , a determination is made that the finger meets certain biometric authentication criteria (e.g., fingerprint is consistent with a registered fingerprint). Upon successful authentication, in  FIG. 34C , electronic device  3400  automatically inputs credential information in username field  3408  and/or password field  3410 , and submits the credential information for user authentication (e.g., submits the information without requiring further input from the user). Upon successful user authentication, electronic device  3400  provides access to restricted content (e.g., content that can only be seen once a user has logged in) in account user interface  3416  of  FIG. 34D . 
     Alternatively, if a determination is made that the finger does not meet certain biometric authentication criteria, electronic device  3400  forgoes inputting and submitting the credential information and displays failure interface  3418 , as shown in  FIG. 34E . Failure interface  3418  can be displayed when a user has reached the maximum number of failed biometric authentication attempts. If the maximum number of failed biometric authentication attempts have been reached, fingerprint sensor  3414  is not available for biometric authentication. 
       FIG. 34F  illustrates log-in user interface  3404 - 1 , which is displayed when biometric authentication is not available using fingerprint sensor  3414  (e.g., when such authentication is disabled via a user-selectable setting or when a maximum number of attempts has been exceeded). In response to detecting a request to display a log-in user interface, a determination is made that biometric authentication using fingerprint sensor  3414  is not available. Upon this determination, electronic device  3400  displays log-in user interface  3404 - 1  without prompt  3406 . Electronic device  3400  displays submit affordance  3420 - 1  in its original, unmodified state, where text  3422  (“LOGIN”) is displayed in submit affordance  3420 - 1 . 
     In some examples, electronic device  3400  does not immediately display prompt  3406  in response to a request to load a log-in user interface. Instead, electronic device  3400  displays prompt  3406  after receiving selection of a fillable field in order to enter text. In  FIG. 34G , electronic device  3400  initially displays log-in user interface  3404 - 1  without prompt  3406 . Electronic device  3400  detects tap gesture  3424  on password field  3410 . In response to detecting tap gesture  3424 , electronic device  3400  displays virtual keyboard  3426  (e.g., a keyboard for inputting one or more characters) and cursor  3428  in password field  3410 , as shown in  FIG. 34H . Further in response to tap gesture  3424 , electronic device  3400  displays log-in user interface  3404  with prompt  3406  located in submit affordance  3420 . 
     In  FIG. 34I , electronic device  3400  receives input via virtual keyboard  3426  corresponding to entry of one or more characters (e.g., character  3430 ). In response to receiving input of character  3430 , electronic device  3400  again displays log-in user interface  3404 - 1  without prompt  3406 . Electronic device  3400  displays submit affordance  3420 - 1  in its original, unmodified state, where text  3422  is displayed in submit affordance  3420 - 1 . 
     In  FIG. 34J , after receiving the input via virtual keyboard  3426 , electronic device  3400  detects tap gesture  3432  on submit affordance  3420 - 1 . In response to detecting tap gesture  3432 , electronic device  3400  submits the one or more characters in username field  3408  and password field  3410  for user authentication. Upon successful user authentication, electronic device  3400  provides access to restricted content (e.g., content that can only be seen once a user has logged in) in account user interface  3416  of  FIG. 34K . 
     In some examples, successful user authentication via fingerprint authentication (as described with respect to  FIGS. 34A-34D ) results in a certain outcome (e.g., access to a restricted application, webpage, or account). In some examples, successful user authentication by typing and submitting credential information (as described with respect to  FIGS. 34F-34K ) results in the same outcome (e.g., access to a restricted application, webpage, or account). 
       FIG. 34L  illustrates that prompt  3406  can be displayed in other locations on a log-in user interface and that some elements discussed with respect to interfaces  3404  and  3404 - 1  can be omitted. In  FIG. 34L , in response to detecting a request to display a log-in user interface and if biometric authentication is available, electronic device  3400  displays log-in user interface  3404 - 2  where prompt  3406  is displayed in password field  3410  and a submit affordance (e.g.,  3420 ,  3420 - 1 ) is not displayed. 
     In  FIG. 34M , while displaying log-in user interface  3404 - 2 , electronic device  3400  detects finger  3412  using fingerprint sensor  3414 . In response to detecting finger  3412 , a determination is made that the finger meets certain biometric authentication criteria (e.g., fingerprint is consistent with a registered fingerprint). Upon successful authentication, electronic device  3400  automatically submits credential information for user authentication. Upon successful user authentication, electronic device  3400  provides access to restricted content (e.g., content that can only be seen once a user has logged in). 
     Alternatively, if a determination is made that the finger does not meet certain biometric authentication criteria (e.g., fingerprint is not consistent with a registered fingerprint), electronic device  3400  forgoes submitting the credential information. Additionally, upon failed biometric authentication, electronic device  3400  displays log-in user interface  3404 - 1  including the previously hidden submit affordance (e.g.,  3420 ,  3420 - 1 ) (shown in  FIG. 34N ). Further, upon failed biometric authentication, electronic device  3400  prompts a user for manual entry by displaying cursor  28  in a fillable field such as password field  3410 . 
       FIG. 35  is a flow diagram illustrating a method for indicating the availability of biometric authentication using an electronic device in accordance with some examples. Method  3500  is performed at a device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) with a display (e.g.,  3402 ) and one or more biometric sensors (e.g.,  3403 ,  3414 ) (e.g., a fingerprint sensor, a contactless biometric sensor (e.g., a biometric sensor that does not require physical contact, such as a thermal or optical facial recognition sensor), an iris scanner). In some examples, the one or more biometric sensors (e.g.,  3403 ) include one or more cameras. In some examples, the display (e.g.,  3402 ) is a touch-sensitive display. In some examples, the display (e.g.,  3402 ) is not a touch sensitive display. 
     Some operations in method  3500  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. As described below, method  3500  provides an intuitive way for indicating the availability of biometric authentication. The method reduces the cognitive burden on a user for determining the availability of biometric authentication, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to identify the availability of biometric authentication faster and more efficiently conserves power and increases the time between battery charges. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) detects ( 3502 ) a predefined operation (e.g., a request to load and/or display the user interface, a selection of a particular element of the user interface) corresponding to a credential submission (e.g., log-in) user interface (e.g.,  3404 ) having a credential submission (e.g., log-in) user interface element (e.g.,  3408 ,  3410 ) (e.g., fillable field such as a username or password). 
     In response ( 3504 ) to detecting the predefined operation, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) proceeds to blocks  3506 - 3516 . 
     In response ( 3504 ) to detecting the predefined operation and in accordance with ( 3506 ) a determination that biometric authentication (e.g., Touch ID, Face ID) via the one or more biometric sensors (e.g.,  3403 ,  3414 ) is available, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) displays ( 3508 ), on the display (e.g.,  3402 ), the credential submission (e.g., log-in) user interface (e.g.,  3404 ) with a visual indication (e.g.,  3406 ) that presentation of a biometric feature (e.g.,  3412 ) that meets biometric authentication criteria to the one or more biometric sensors (e.g.,  3403 ,  3414 ) will cause credentials to be submitted via the credential submission user interface element (e.g.,  3408 ,  3410 ). 
     In some examples, the credential submission user interface is generated based on an electronic document (e.g., an HTML document) and the credential submission user interface element is an input element (e.g., log-in button) for submitting the credentials. In some examples, if biometric authentication is available, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ), rather than rendering and displaying the credential-entry element in a first state (e.g., a default state, a state that is displayed when biometric authentication is not available), displays a biometric authentication element (e.g., instructions for providing the required biometric authentication input (e.g., a fingerprint) in place of the credential submission user interface element.) Displaying a prompt to a user indicating that placing their finger on a sensor results in automatically logging in provides the user with feedback about the current state of the device (e.g., biometric authentication is available) and provides feedback to the user indicating an efficient option for logging in. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, in response ( 3504 ) to detecting the predefined operation and in accordance with ( 3506 ) the determination that biometric authentication via the one or more biometric sensors (e.g.,  3403 ,  3414 ) is available, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) forgoes ( 3516 ) displaying, on the display (e.g.,  3402 ), the credential submission affordance (e.g.,  3420 ) (e.g., do not display the log-in button). Omitting the display of a log-in button encourages the user to pursue an efficient method of logging in, thereby providing improved feedback. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, in response ( 3504 ) to detecting the predefined operation and in accordance with ( 3510 ) a determination that biometric authentication via the one or more biometric sensors (e.g.,  3403 ,  3414 ) is not available, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) displays ( 3512 ), on the display (e.g.,  3402 ), the credential submission (e.g., log-in) user interface (e.g.,  3404 - 1 ) without displaying the visual indication (e.g.,  3406 ). Forgoing the display of the prompt to log-in via biometric authentication provides the user with feedback about the current state of the device, for it indicates to the user that log-in via biometric authentication is not available. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, further in response ( 3504 ) to detecting the predefined operation and in accordance with ( 3510 ) the determination that biometric authentication via the one or more biometric sensors (e.g.,  3403 ,  3414 ) is not available, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) displays ( 3514 ), on the display (e.g.,  3402 ), a credential submission affordance (e.g.,  3420 ) (e.g., a touch activated log-in button that is associated with one or more fillable fields). Receiving an input (e.g.,  3432 ) corresponding to selection of the credential submission affordance (e.g.,  3420 ) causes credentials to be submitted via the credential submission user interface element (e.g.,  3408 ,  3410 ) (e.g., causes credentials to be submitted without use of biometric authentication). 
     In accordance with some examples, while displaying the credential submission user interface (e.g.,  3404 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) detects, via the one or more biometric sensors (e.g.,  3403 ,  3414 ), a biometric feature (e.g.,  3412 ) of a respective type. In response to detecting the biometric feature (e.g.,  3412 ) of the respective type, and in accordance with a determination that the biometric feature (e.g.,  3412 ) meets the biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) submits credentials via the credential submission user interface element (e.g.,  3408 ,  3410 ) (e.g., successful authentication results in submitting credentials). In response to detecting the biometric feature (e.g.,  3412 ) of the respective type, and in accordance with a determination that the biometric feature (e.g.,  3412 ) does not satisfy biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) forgoes submitting credentials via the credential submission user interface element (e.g.,  3408 ,  3410 ). Forgoing the submission of credentials based on not meeting biometric authentication criteria provides security and can prevent unauthorized users from initiating sensitive operations. Providing improved security enhances the operability of the device and makes the user-device interface more efficient (e.g., by restricting unauthorized access) which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     In accordance with some examples, the credential submission user interface element (e.g.,  3408 ,  3410 ) includes one or more fillable fields. 
     In accordance with some examples, displaying the credential submission user interface (e.g.,  3404 ,  3404 - 1 ,  3404 - 2 ) includes displaying the credential submission user interface element prefilled with the credentials (e.g., default username is prefilled) to be submitted via the credential submission user interface element (e.g.,  3408 ,  3410 ). Prefilling a default username provides the user with a capability to log-in using fewer inputs. Performing an operation with a reduced number of inputs enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) receives selection of a fillable field (e.g.,  3408 ,  3410 ) of the one or more fillable fields. In response to receiving the selection of the fillable field, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) displays, on the display (e.g.,  3402 ), a character input interface (e.g.,  3426 ) (e.g., a keypad or keyboard that includes character entry keys for entering a password or passcode). 
     In accordance with some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) receives input (e.g.,  3430 ) corresponding to entry of one or more characters via the character input interface (e.g.,  3426 ) (e.g., via character entry keys) in the fillable field. In some examples, the character input interface includes character entry keys. Subsequent to receiving the input, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) receives selection of a second credential submission affordance (e.g.,  3420 ) (e.g., log-in button). In response to receiving the selection of the second credential submission affordance, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) submits the one or more characters in the fillable field (e.g.,  3408 ,  3410 ) for credential verification. 
     In accordance with some examples, the visual indication (e.g.,  3406 ) that presentation of a biometric feature (e.g.,  3412 ) that meets biometric authentication criteria to the one or more biometric sensors (e.g.,  3403 ,  3414 ) will cause credentials to be submitted via the credential submission user interface element (e.g.,  3408 ,  3410 ) is displayed in a fillable field (e.g.,  3410 ) of the one or more fillable fields (e.g., username field, password field). Displaying a prompt to a user indicating that placing their finger on a sensor results in automatically logging in provides the user with feedback about the current state of the device (e.g., biometric authentication is available) and provides feedback to the user indicating an efficient option for logging in. Displaying the prompt in the password field can provide feedback as to the operation (e.g., autofilling the password field) that will be performed upon successful authentication. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some examples, the predefined operation is a request to display the credential submission interface (e.g.,  3404 ,  3404 - 1 ,  3404 - 2 ) on the display (e.g.,  3402 ) (e.g., load the credential submission user interface, scroll the credential submission user interface into view, zoom into the credential submission user interface, reveal the credential submission user interface from a hidden user interface element). In some examples, the predefined operation that is a request to display the credential submission interface is also a request to display a first portion of respective content, as described with respect to method  3300  (e.g., method  3300  at  3302 ). 
     In accordance with some examples, the predefined operation is detected while displaying the credential submission interface (e.g.,  3404 ,  3404 - 1 ) and the predefined operation includes an input (e.g.,  3424 ) directed to a portion of the credential submission user interface (e.g., a user input (e.g., tap) on the credential submission user interface or user input on a fillable field such a username or password field). 
     In accordance with some examples, in accordance with submission of the one or more characters in the fillable field (e.g.,  3408 ,  3410 ) for credential verification and in response to receiving the selection of the second credential submission affordance (e.g.,  3420 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) provides a first result. In accordance with submission of credentials via the credential submission user interface element (e.g.,  3408 ,  3410 ) and in response to a determination that a biometric feature (e.g.,  3412 ) detected via the one or more biometric sensors (e.g.,  3403 ,  3414 ) meets the biometric authentication criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  1700 ,  3400 ) provides the first result. In some examples, submitting (e.g., successfully submitting) credentials (e.g., valid credentials) via a password or passcode entered via the credential submission user interface element results in the same outcome (e.g., access to a restricted application, webpage, or account) as successful authentication via biometric authentication). 
     Note that details of the processes described above with respect to method  3500  (e.g.,  FIG. 33 ) are also applicable in an analogous manner to the methods described below and above. For example, method  3500  optionally includes one or more of the characteristics of the various methods described above with reference to methods  800 ,  1000 ,  1200 ,  1400 ,  1600 ,  2000 ,  2200 ,  2500 ,  2700 ,  2900 ,  3100 , and  3300 . For example, the enrolled biometric data described in method  1200  can be used to perform biometric authentication as described with respect to method  3500 . As a further example, the re-authentication criteria of method  3100  can be used in conjunction with method  3500  to control when biometric is available. For brevity, these details are not repeated below. 
     In some examples (e.g., in some examples of methods  1600 ,  1800 ,  2000 ,  2200 ,  2900 ,  3100 ,  3300 , and  3500 ), the electronic device limits the permitted number of biometric authentication attempts (e.g., in order to provide improved security by preventing brute force attempts to bypass security and to conserve device resources) that can be made before biometric authentication is disabled (e.g., disabled until successful authentication, via alternative means, occurs). In some such examples, ceasing use of the biometric sensor (e.g., forgoing further biometric authentication retries) prior to exhaustion of the permitted/limited number of attempts avoids the user consuming the permitted number of attempts on repeated requests (e.g., repeated requests of the same type), thereby conserving at least one attempt for requests for other operations that require biometric authentication (e.g., requests for other, more critical operations). Conserving at least one attempt enhances the operability of the device and makes the user-device interface more efficient (e.g., by avoiding exhaustion of authentication attempts on repeated, similar requests) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In addition, conserving at least one biometric authentication attempt can reduce the instances in which a user must provide alternative, non-biometric authentication (e.g., such as password or passcode authentication), which, in turn, can promote the use of more secure (e.g., more complex) passwords/passcodes, as the user is not disincentivized from using more secure passwords/passcodes by the need to frequently use such passwords/passcodes when biometric authentication becomes disabled due to exhaustion of permitted attempts. Promoting the use of more secure passwords/passcodes enhances the operability of the device by reducing the risk of unauthorized access. 
       FIGS. 36A-36L  illustrate exemplary user interfaces for retrying biometric authentication at a credential entry user interface, in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIGS. 37A-37B . 
       FIG. 36A  illustrates electronic device  3600  (e.g., portable multifunction device  100 , device  300 , device  500 ). In the exemplary examples illustrated in  FIGS. 36A-36L , electronic device  3600  is a smartphone. In other examples, electronic device  3600  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  3600  includes display  3602 , one or more input devices (e.g., touchscreen of display  3002 , button  3604 , and a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In  FIG. 36A , the electronic device includes biometric sensor  3603 . In some examples, the biometric sensor is one or more biometric sensors that can include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, biometric sensor  3603  is biometric sensor  703 . In some examples, the one or more biometric sensors include one or more fingerprint sensors (e.g., a fingerprint sensor integrated into a button). In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     At  FIG. 36A , electronic device  3600  displays locked state user interface (UI)  3606  including lock icon  3608 , which provides an indication to the user that electronic device  3600  is in a locked state. Because electronic device  3600  is in a locked state, the user is unable to view the restricted content of notification  3610 A (e.g., the message from John Appleseed). 
     At  FIG. 36B , the user wishes to unlock electronic device  3600  to access restricted content on the device (e.g., the message from John Appleseed, home screen  3628  of  FIG. 36L , the most recently used application). Unlocking the device requires successful authentication of the user. To request unlocking of the device, the user performs an upward swipe starting from within region  3612 A, which is a predefined region adjacent to the bottom edge of display  3602 . 
     While displaying locked state UI  3606 , electronic device  3600  receives input  3614 A (e.g., an upward swipe). While displaying locked state UI  3606 , electronic device  3600  requires that an upward swipe start from within region  3612 A to trigger a request to unlock the device. In response to receiving input  3614 A, electronic device  3600  determines whether input  3614 A starts from within region  3612 A. 
     Upon detecting input  3614 A (e.g., an input that begins within region  3612 A), electronic device  3600  initiates biometric authentication, and determines whether biometric authentication is currently enabled (or available for use) on the device. Biometric authentication can be unavailable for a variety of reasons including, for example, that biometric authentication has failed more than a predetermined number of times (e.g., 5, 10, 15) since the last successful authentication with the device. 
     In some examples, instead of receiving input  3614 A, electronic device  3600  receives any one of inputs  3614 B-E (e.g., swipe inputs that move a similar distance as input  3614 A). Like input  3614 A, each of inputs  3614 B-E is an upward swipe. In some examples, because input  3614 B also starts within region  3614 A, electronic device  3600  treats input  3614 A and  3614 B the same (e.g., electronic device  3600  has the same response to both inputs). In contrast, in some examples, the response of electronic device  3600  to inputs  3614 C-E is different from the response to inputs  3614 A-B. Specifically, in some examples, in response to receiving any one of inputs  3614 C-E, electronic device  3600  does not initiate biometric authentication, as described below with respect to  FIG. 36C . Instead, electronic device  3600  displays one or more notifications (e.g.,  3610 A-E) (e.g., unread notifications) while maintaining the device in a locked state, as depicted in  FIG. 36K  (e.g., by scrolling a portion of the wake screen user interface (e.g.,  3606 ) to display one or more notifications that were previously not visible on the display where the amount of scrolling is optionally determined based on a magnitude or velocity of movement of the contact). 
     At  FIG. 36C , in response to input  3614  and upon determining that biometric authentication is currently enabled, electronic device  3600  attempts to biometrically authenticate the user (e.g., attempts to match information about a user&#39;s face obtained using biometric sensor  3603  with stored authorized credentials). While attempting to biometrically authenticate the user, electronic device  3600  displays (e.g., replaces display of locked state UI  3606  with) interstitial interface  3616  with authentication glyph  3618 . Authentication glyph  3618 , which includes a plurality of rings that rotate about an axis that is parallel to the display so that they appear to rotate out of a z axis of the display, provides an indication to the user that biometric authentication is being performed. 
     While attempting to biometrically authenticate the user, electronic device  3600  uses biometric sensor  3603  to determine whether certain biometric authentication criteria have been met. More specifically, electronic device  3600  captures and processes (e.g., analyzes) the biometric data from biometric sensor  3603  to determine, based on the biometric data, whether the biometric feature (or a portion thereof) satisfies biometric authentication criteria (e.g., determine whether the biometric data matches, within a threshold, a biometric template (e.g., stored authorized credentials)). After initiating biometric authentication, electronic device  3600  determines that biometric authentication has failed (e.g., the biometric data from biometric sensor  3603  does not match the stored authorized credentials). 
     At  FIG. 36D , upon determining that biometric authentication has failed, electronic device  3600  displays an animation of lock icon  3608  alternating between different positions to simulate a “shake” effect. This “shake” animation provides an indication to the user that electronic device  3600  was unable to biometrically authenticate the user. 
     As depicted in  FIG. 36E , further in response to determining that biometric authentication has failed, electronic device  3600  displays (e.g., replaces display of interstitial interface  3616  with) passcode entry UI  3620 , which provides an alternative (e.g., non-biometric) method of authenticating the user at electronic device  3600 . Passcode entry UI  3620  includes lock icon  3608  and a plurality of input keys for inputting (or entering) a password or passcode. Passcode entry UI  3620  also includes prompt  3622 A, which prompts the user to either swipe up to retry biometric authentication or enter a passcode (or password) to authenticate the user (e.g., non-biometrically). Electronic device  3600  displays prompt  3622 A upon determining that biometric authentication is currently enabled on the device. Additionally, upon determining that biometric authentication is currently enabled, electronic device  3600  displays unlock indication  3624 , which provides an indication of an approximate location on display  3602  from which a user can start an upward swipe to retry biometric authentication. 
     At  FIG. 36E , the user seeks to retry biometric authentication rather than input a password or passcode to authenticate. While displaying passcode entry UI  3620 , electronic device  3600  receives input  3614 C, which starts outside region  3612 A of  FIG. 36B . 
     Nevertheless, input  3614 C triggers retrying biometric authentication because input  3614 C starts from within region  3612 B. Notably, region  3612 B is larger than region  3612 A because the parameters for where the upward swipe must start to initiate biometric authentication is relaxed on passcode entry UI  3620  in comparison to locked state UI  3606 . 
     In some examples, instead of receiving input  3614 C, electronic device receives any one of inputs  3614 A-B and  3614 D-E. In some examples, in light of the relaxed parameters on passcode entry UI  3620 , all but input  3614 E would trigger retrying biometric authentication. In some examples, in response to receiving input  3614 E, electronic device  3600  determines that input  3614 E does not start from within region  3612 B, and in response, does not retry biometric authentication. 
     At  FIG. 36F , in response to receiving input  3614 C, electronic device  3600  device determines that input  3614  starts from within region  3612 B. Upon determining that input  3614  starts from within region  3612 B, electronic device  3600  retries biometric authentication. While retrying biometric authentication, electronic device  3600  displays (e.g., replaces display of lock icon  3608  with) authentication glyph  3618 . Authentication glyph  3618  provides an indication to the user that biometric authentication is being performed. 
     While retrying biometric authentication, electronic device  3600  determines that biometric authentication is successful (e.g., the biometric data obtained using biometric sensor  3603  matches the stored authorized credentials). 
     At  FIGS. 36G-36H , upon determining that biometric authentication is successful, electronic device  3600  transitions from a locked state to an unlocked state. Electronic device  3600  provides an indication of this transition by displaying an animation of lock icon  3608  transitioning to unlock icon  3626  of  FIG. 36H , which provides an indication that the electronic device  3600  has transitioned to an unlocked state. Additionally, upon determining that biometric authentication is successful and after displaying unlock icon  3626 , electronic device  3600  provides access to restricted content. For example, electronic device  3600  displays home screen  3628  of  FIG. 36L  or the most recently used application (e.g., a user interface of the most recently used application (e.g., messaging application interface  2616  of  FIG. 26G )). 
     In some examples, instead of determining at  FIG. 36C  that biometric authentication has failed, electronic device  3600  determines that biometric authentication is successful. In some examples, upon determining that biometric authentication is successful, electronic device  3600  transitions to an unlocked state and displays unlock icon  3626 , as described above with respect to  FIGS. 36G-36H . Additionally, in some examples, upon determining that biometric authentication is successful and after displaying unlock icon of  FIG. 36H , electronic device  3600  displays home screen  3628 . (Home screen  3628  can include some or all of the features of home screen interface  2614  of  FIG. 26D .) In some examples, upon determining that biometric authentication is successful and after displaying unlock icon  3626 , electronic device  3600  displays the most recently used application (e.g., messaging application interface  2616  of  FIG. 26G ). 
     In some examples, instead of determining that biometric authentication is enabled on the device as described above with respect to  FIGS. 36B-36C , electronic device  3600  determines that biometric authentication is not currently enabled (e.g., because biometric authentication has been (manually) disabled by the user or because a predetermined biometric authentication have been attempted without success). In some examples, upon determining that biometric authentication is not currently enabled, electronic device  3600  displays prompt  3622 B of  FIG. 36I  instead of prompt  3622 A of  FIG. 36E . In contrast to prompt  3622 A, prompt  3622 B only prompts the user to enter a passcode (or password) to authenticate the user without prompting the user to swipe to retry biometric authentication. Additionally, in some examples, upon determining that biometric authentication is not currently enabled, electronic device  3600  does not display unlock indication  3624 , as depicted in  FIG. 36I . As described above, unlock indication  3624  provides an indication of an approximate location on display  3602  from which a user can start an upward swipe to retry biometric authentication. In some examples, because biometric authentication is not currently enabled, electronic device  3600  does not display unlock indication  3624 . 
     In some examples, instead of determining at  FIG. 36F  that biometric authentication is successful, electronic device  3600  determines that biometric authentication has failed. In some examples, upon determining that biometric authentication has failed, electronic device  3600  displays an animation of lock icon  3608  alternating between different positions to simulate a “shake” effect (instead of displaying a transition to an unlocked state as described above with respect to  FIGS. 36G-36H ). As described above, this “shake” animation provides an indication to the user that electronic device  3600  was unable to biometrically authenticate the user. 
       FIGS. 37A-37B  are flow diagrams illustrating a method for retrying biometric authentication at a credential entry user interface using an electronic device, in accordance with some examples. Method  3700  is performed at an electronic device (e.g.,  100 ,  300 ,  500 ,  3600 ) with a touch-sensitive display (e.g.,  3602 ) and one or more biometric sensors (e.g.,  3603 ) (e.g., a first biometric sensor of a device with a plurality of biometric sensors) (e.g., a fingerprint sensor, a contactless biometric sensor (e.g., a biometric sensor that does not require physical contact, such as a thermal or optical facial recognition sensor), an iris scanner). In some examples, the one or more biometric sensors include one or more cameras. Some operations in method  3700  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  3700  provides an intuitive way for retrying biometric authentication at a credential entry user interface using an electronic device. The method reduces the cognitive burden on a user for retrying biometric authentication, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to retry biometric authentication faster and more efficiently conserves power and increases the time between battery charges. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  3600 ) displays ( 3706 ), on the touch-sensitive display (e.g.,  3602 ), a credential entry (e.g., passcode, password, pattern) user interface (e.g.,  3620 ) with a plurality of character entry keys. In some examples, the credential entry user interface includes a virtual keypad or virtual keyboard. In some examples, the virtual keypad or virtual keyboard includes a plurality of character entry keys. In some examples, while displaying the credential entry user interface (e.g.,  3620 ), the electronic device receives input corresponding to one or more character entry keys of the plurality of character entry keys. In some examples, in response to (or subsequent to) receiving the input corresponding to the plurality of character entry keys, the electronic device transitions from a locked state (e.g., corresponding to  3606 ) to an unlocked state (e.g., corresponding to  3628 ) in accordance with a determination that the received input corresponds to (or matches) authorized credentials (e.g., a stored passcode or password). 
     While displaying the credential entry user interface (e.g.,  3620 ), the electronic device receives ( 3708 ), via the touch-sensitive display (e.g.,  3602 ), a touch gesture input (e.g.,  3614 A-B) (e.g., a swipe at a predefined location) that includes movement of a contact on the touch-sensitive display. 
     In response ( 3712 ) to receiving the touch gesture input that includes movement of the contact on the touch-sensitive display and in accordance ( 3714 ) with a determination that a first set of one or more criteria are met, the first set of one or more criteria including a requirement that biometric authentication is currently enabled on the electronic device, the electronic device attempts to biometrically authenticate a user of the electronic device based on biometric information captured using the one or more biometric sensors. In some examples, the first set of one or more criteria only includes one criterion. In some examples, biometric authentication can become unavailable (or not enabled on the electronic device) when one or more of the following conditions have been met: the electronic device has not been successfully authenticated since being turned on or restarted; the electronic device has not been unlocked for more than a predetermined amount of time (e.g., 48 hours); the passcode has not been used to unlock the device for more than a predetermined amount of time (e.g., 156 hours); biometric authentication using a biometric feature (e.g., face, fingerprint) has not been used to unlock device for more than predetermined amount of time (e.g., 4 hours); the electronic device has received a remote lock command; biometric authentication has failed more than a predetermined number of times (e.g., 5, 10, 15) since the last successful authentication with the device; and the electronic device has received a power off and/or emergency SOS command. In some examples, the touch gesture input is a request to unlock electronic device  3600 . Providing the user with the capability to retry biometric authentication by performing a touch gesture input at the credential entry user interface enhances the operability of the device by providing additional control of the device without cluttering the UI with additional displayed controls. Providing this capability enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in response ( 3712 ) to receiving the touch gesture input that includes movement of the contact on the touch-sensitive display and in accordance ( 3716 ) with a determination that the first set of one or more criteria are not met (e.g., because biometric authentication is not currently enabled on the device), the electronic device forgoes attempting to biometrically authenticate the user of the electronic device based on biometric information captured using the one or more biometric sensors (e.g.,  3603 ). Forgoing attempting to biometrically authenticate the user when biometric authentication is not enabled improves the security of the device by preventing fraudulent use of the device. 
     In some examples, displaying the credential entry user interface (e.g.,  3620 ) occurs in response to receiving ( 3702 ) a request to perform an operation that requires authentication (e.g., a request to unlock the electronic device (e.g.,  3614 A-B) (e.g., a swipe starting from an edge (e.g., bottom edge) of the display or starting from within a predefined region (e.g., lower portion) of the display)) and failing to biometrically authenticate the user of the electronic device based on biometric information captured using the one or more biometric sensors. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  3600 ) fails to biometrically authenticate the user of the electronic device when the biometric information captured using the one or more biometric sensors does not correspond to (or match) authorized credentials (e.g., stored information about a biometric feature (e.g., face, fingerprint) that are authorized for use in biometric authentication). Displaying the credential entry user interface when a set of conditions has been met provides the user with the capability to authenticate via an alternative method without requiring the user to explicitly request that the credential entry user interface be displayed Performing an operation when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the request to perform the operation that requires authentication (e.g.,  3614 A-B) is a second touch gesture input ( 3704 ) that includes movement of a contact on the touch sensitive display (e.g., a swipe starting from an edge (e.g., bottom edge) of the display or starting from within a predefined region (e.g.,  3612 A) (e.g., lower portion) of the display). In some examples, the set of one or more criteria includes a requirement that the touch gesture input starts at a first region (e.g.,  3612 A) of the display (e.g., a region along a bottom edge of the display) and ends (or progresses through) a second region of the display (e.g., a region above the region along the bottom edge of the display (e.g.,  3612 A)). 
     In some examples, in accordance with a determination that a second set of one or more criteria are met, the second set of one or more criteria including a requirement that biometric authentication is currently enabled on the electronic device, displaying the credential entry user interface (e.g.,  3620 ) includes displaying, on the touch-sensitive display (e.g.,  3602 ), an indication (e.g.,  3622 A) (e.g., text, graphics, icons) to perform a gesture on the touch-sensitive display to attempt biometrically authenticating the user. In some examples, in accordance with a determination that the second set of one or more criteria are not met, the electronic device forgoes displaying the indication to perform the gesture on the touch-sensitive display to attempt biometrically authenticating the user. In some examples, the second set of one or more criteria is the same as the first set of one or more criteria. In some examples, the second set of one or more criteria only includes one criterion. Displaying an indication to perform a gesture when biometric authentication is available provides the user with feedback as to the current state of the device (e.g., that biometric authentication is available) and prompts the user to perform the gesture associated with the indication. Moreover, not displaying the indication to perform the gesture when biometric authentication is not available also provides the user with feedback as to the current state of the device (e.g., that biometric authentication is not available). Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in accordance with a determination that a third set of one or more criteria are met, the third set of one or more criteria including a requirement that biometric authentication is currently enabled on the electronic device, displaying the credential entry user interface (e.g.,  3620 ) includes displaying, on the touch-sensitive display (e.g.,  3602 ), a user interface element (e.g.,  3624 ) (e.g., a graphical element, a horizontal bar, a home affordance, an indication of a location from which a user should swipe to attempt biometric authentication) adjacent to an edge of the touch-sensitive display (e.g., bottom edge of the display). In some examples, the third set of one or more criteria is the same as the first set of one or more criteria. In some examples, the third set of one or more criteria only includes one criterion. In some examples, in accordance with a determination that the third set of one or more criteria are not met, the electronic device (e.g.,  100 ,  300 ,  500 ,  3600 ) forgoes displaying the user interface element. In some examples, the set of one or more criteria includes a requirement that the touch gesture input starts at a first region (e.g.,  3612 A) of the display (e.g., a region along a bottom edge of the display) and ends at (or progresses through a) a second region of the display (e.g., a region above the region along the bottom edge of the display. In some examples, the user interface element (e.g.,  3624 ) is displayed at a location that corresponds (e.g., that is within) to the first region of the display. Displaying the user interface element adjacent to the edge of the display when biometric authentication is available provides feedback to the user about the current state of the device and feedback as to how the user can request unlocking of the device. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, while attempting to biometrically authenticate the user of the electronic device based on biometric information captured using the one or more biometric sensors, the electronic device (e.g.,  100 ,  300 ,  500 ,  3600 ) displays, on the touch-sensitive display, an animation with one or more moving elements (e.g.,  3618 ) that indicate that biometric authentication is occurring (e.g., displaying an animation that includes one or more rings (e.g., a graphical icon) moving on the display). In some examples, the animation provides an indication that biometric information is being processed. In some examples, the animation includes rings rotating around an object (e.g., a sphere). In some examples, the sphere is visible. In some examples, the sphere is not visible. Displaying one or more moving elements indicating that biometric authentication is occurring provides the user with feedback about the current state of the device (e.g., biometric authentication is being performed) and that the user does not need to take any action at this time. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, displaying the animation with the one or more moving elements includes transitioning from the animation with one or more moving elements to a lock icon (e.g.,  3608 ) (e.g., an icon indicative of a locked state). In some examples, after transitioning from the animation with one or more moving elements (e.g.,  3618 ) to the lock icon and in accordance with a determination that the biometric information captured using the one or more biometric sensors corresponds to (e.g., matches) authorized credentials (e.g., stored information about a biometric feature (e.g., face, fingerprint) that are authorized for use in biometric authentication), the electronic device transitions from a locked state to an unlocked state. In some examples, transitioning the electronic device from a locked state to an unlocked state includes displaying an animation of the lock icon transitioning to an unlock icon (e.g.,  3626 ) (e.g., an icon indicative of an unlocked state). In some examples, after transitioning from the animation with one or more moving elements to the lock icon and in accordance with a determination that the biometric information captured using the one or more biometric sensors does not correspond to (e.g., does not match) the authorized credentials, the electronic device displays, on the touch-sensitive display (e.g.,  3602 ), an animation with the lock icon (e.g.,  3608 ) alternating between a first position and a second position, the second position being different from the first position. In some examples, the animation with the lock icon is an animation of the lock icon shaking (e.g., side to side, rotating back and forth). In some examples, the electronic device displays an animation involving the lock icon to indicate that biometric authentication has failed. In some examples, a tactile output is provided in combination with the shaking lock icon. In some examples, no tactile output is provided. In some examples, in accordance with a determination that the biometric information captured using the one or more biometric sensors does not correspond to or does not match the authorization credentials, the electronic device (e.g.,  100 ,  300 ,  500 ,  3600 ) maintains the locked state of the electronic device. Displaying an animation of the lock icon transitioning to an unlock icon provides the user with feedback about the current state of the device (e.g., that biometric authentication is successful, that the device has been unlocked, that the user can now access restricted content). Moreover, displaying an animation of the lock icon shaking provides the user with feedback about the current state of the device (e.g., that biometric authentication has failed) and prompts the user to take further action. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the touch gesture input that includes movement of the contact on the touch-sensitive display starts ( 3710 ) from a location that is away from (e.g., not substantially near) an edge of the touch-sensitive display (e.g., bottom edge of the display). In some examples, the location that is away from the edge of the touch-sensitive display (e.g.,  3602 ) includes a location closer to the center of the display than to the edge. In some examples, the location that is away from the edge of the touch-sensitive display includes a location that is more than a threshold distance from the edge of the display (or outside a predefined region (e.g.,  3612 A)). In some examples, the threshold distance (or predefined region) is used on the wake screen to determine whether to dismiss the wake screen when a swipe input starts less than the threshold distance away from the edge of the display. In some examples, the threshold distance (or predefined region (e.g.,  3612 A)) is used to perform a different operation on the wake screen such as scrolling content (e.g.,  3610 A-E) on the wake screen when a swipe input starts more than the threshold distance away from the edge of the display (or outside a predefined region (e.g.,  3612 A)). In some examples, the parameters for where the touch gesture input must start are relaxed for the credential entry user interface (e.g.,  3620 ). Relaxing the parameters at the credential entry user interface for where the touch gesture input must start enhances the operability of the device by allowing less precise gestures to initiate biometric authentication. The parameters are relaxed because the user has already conveyed a desire to initiate biometric authentication. As a result, there is less risk at the credential entry user interface that the user does not intend to initiate biometric authentication. Allowing less precise gesture to initiate biometric authentication after the user has already conveyed a desire to initiate biometric authentication enhances the operability of the device and makes the user-device interface more efficient which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     In some examples, in response to receiving the touch gesture input (e.g.,  3614 C-E) that includes movement of the contact on the touch-sensitive display starting from the location that is away from the edge of the touch-sensitive display and in accordance ( 3718 ) with a determination that the biometric information captured using the one or more biometric sensors corresponds to (e.g., matches) authorized credentials (e.g., stored information about a biometric feature (e.g., face, fingerprint) that are authorized for use in biometric authentication), the electronic device transitions from a locked state to an unlocked state. In some examples, transitioning the electronic device to an unlocked state includes displaying an unlocked user interface (e.g., a user interface indicative of an unlocked state, such as a home screen (e.g.,  3628 ) or a most recently used application). 
     In some examples, prior to displaying the credential entry user interface, the electronic device (e.g.,  100 ,  300 ,  500 ,  3600 ) displays, on the touch-sensitive display (e.g.,  3602 ), a lock user interface (e.g.,  3606 ) (e.g., a user interface indicative of a locked state of the electronic device, a wake screen, a lock screen). In some examples, the lock user interface is different from the credential entry use interface (e.g.,  3620 ). In some examples, while displaying the lock user interface, the electronic device receives, via the touch-sensitive display (e.g.,  3602 ), a touch gesture input (e.g.,  3614 A-B) with a starting location (e.g., an upward swipe). In response to receiving the touch gesture input with the starting location and in accordance with a determination that a fourth set of one or more criteria are met, the fourth set of one or more criteria including a requirement that the starting location of the touch gesture input is located substantially near an edge (e.g., within a predefined region (e.g.,  3612 A), within a predefined distance from the edge; a location closer to the edge than to the center of the display) of the touch-sensitive display, the electronic device initiates biometric authentication. In some examples, the fourth set of one or more criteria only includes one criterion. In some examples, initiating biometric authentication includes attempting to biometrically authenticate a user of the electronic device based on biometric information captured using the one or more biometric sensors. In some examples, in response to receiving the touch gesture input with the starting location and in accordance with a determination that the fourth set of one or more criteria are not met, the electronic device forgoes initiating biometric authentication. 
     Note that details of the processes described above with respect to method  3700  (e.g.,  FIGS. 37A-37B ) are also applicable in an analogous manner to the methods described below. For example, method  3900 , method  4100 , and/or method  4300  optionally include one or more of the characteristics of the various methods described above with reference to method  3700 . For example, the processes for retrying biometric authentication, as described above with respect to method  3700 , can be used to retry biometric authentication to authorize payment of goods, as described with respect to method  4100 . Similarly, the process for retrying biometric authentication can be used to retry biometric authentication in the processes described with respect to method  3900 . For brevity, these details are not repeated below. 
       FIGS. 38A-38AD  illustrate exemplary user interfaces for providing indications of error conditions during biometric authentication, in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIGS. 39A-39B . 
       FIG. 38A  illustrates electronic device  3800  (e.g., portable multifunction device  100 , device  300 , device  500 ). In the exemplary examples illustrated in  FIGS. 38A-38AD , electronic device  3800  is a smartphone. In other examples, electronic device  3600  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  3600  includes display  3802 , one or more input devices (e.g., touchscreen of display  3802 , button  3804 , and a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In  FIG. 38A , the electronic device includes biometric sensor  3803 . In some examples, the biometric sensor is one or more biometric sensors that can include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, biometric sensor  3803  is biometric sensor  703 . In some examples, the one or more biometric sensors include one or more fingerprint sensors (e.g., a fingerprint sensor integrated into a button). In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     At  FIG. 38A , a user learns from notification  3808  that she has received a message from John Appleseed. The user wishes to view the restricted content of notification  3808  (e.g., the message from John Appleseed), but is unable to do so, as electronic device  3800  is currently in a locked state. Electronic device  3800  displays a locked state user interface (UI) with lock icon  3806 , which provides an indication that electronic device  3800  is in a locked state. Viewing the restricted content of notification  3808  requires successful authentication (e.g., determining that information (or data) about a biometric feature obtained using biometric sensor  3803  corresponds to (or matches) stored authorized credentials). To view the restricted content of notification  3808 , the user lifts (or raises) electronic device  3800  (e.g., from a substantially horizontal orientation to the orientation of the device as depicted in the user&#39;s hand in  FIG. 38A ). Electronic device  3800  detects the change in orientation of electronic device  3800  and, in response, initiates biometric authentication. In some examples, after initiating biometric authentication, electronic device  3800  determines that biometric authentication is successful. In some examples, upon determining that biometric authentication is successful, electronic device  3800  transitions from a locked state to an unlocked state, and displays the restricted content of notification  3808 . 
     After initiating biometric authentication (e.g., prior to successful authentication), electronic device  3800  determines whether a face is detected by biometric sensor  3803 . At  FIG. 38B , upon determining that a face is detected, electronic device  3803  displays authentication glyph  3810 , which includes a plurality of rings that rotate spherically. Authentication glyph  3810  provides an indication that biometric authentication is being performed. In some examples, electronic device  3800  displays an animation of lock icon  3806  morphing into authentication glyph  3810 . In some examples, upon determining that no face is detected using biometric sensor  3803 , electronic device  3803  maintains a locked state, and does not display authentication glyph  3810 . 
     After detecting the presence of a face, electronic device  3800  determines that authentication is unsuccessful due to failure to obtain sufficient information about the user&#39;s face using biometric sensor  3803 . Specifically, as depicted by  FIG. 38B , biometric sensor  3803  is positioned outside acceptable distance range  3812  (e.g., above the maximum threshold range), resulting in a failure to obtain sufficient information about the user&#39;s face. Upon determining that biometric authentication is unsuccessful due to the user&#39;s face being outside acceptable distance range  3812 , electronic device  3800  maintains the device in a locked state and does not display the restricted content of notification  3808 . In some examples, electronic device  3800  maintains the device in a locked state and does not display the restricted content of notification  3808  upon determining authentication is unsuccessful and that no error condition exists. In some examples, upon determining that authentication is unsuccessful (e.g., due to captured biometric information not matching an authorized biometric information profile (e.g., stored authorized credentials)) and that no error condition exists (e.g., no condition preventing capture of sufficient biometric information), electronic device  3800  maintains a locked state and automatically retries biometric authentication. In some examples, while retrying biometric authentication, electronic device  3800  continues to display authentication glyph  3810  in  FIG. 38B . 
     As depicted in  FIGS. 38C-38G , upon determining that biometric authentication is unsuccessful due to the user&#39;s face being outside acceptable distance range  3812 , electronic device  3800  displays an animation of authentication glyph  3810  morphing into error indication  3814 A such that error indication  3814 A replaces the display of authentication glyph  3810 . At  FIG. 38G , electronic device  3800  displays error indication  3814 A, which prompts the user to take an action to correct the error condition underlying error indication  3814 A. Specifically, error indication  3814 A prompts the user to move her face closer to biometric sensor  3803 . Error indication  3814 A also suggests to the user that the user&#39;s face is too far away from biometric sensor  3803 , which is the cause of error indication  3814 A. As long as the user&#39;s face is outside acceptable distance range  3812 , electronic device  3800  will continue to determine that error indication  3814 A exists. Upon determining that error indication  3814 A still exists, electronic device  3800  does not attempt retrying biometric authentication. It is noted that electronic device  3800  displays error indication  3814 A at a position coinciding with the position of lock icon  3806  in  FIG. 38A . Further, electronic device  3800  displays error indication  3814 A on a portion of display  3802  that is adjacent to biometric sensor  3803  to suggest to the user that error indication  3814 A is associated with (or corresponds to) biometric sensor  3803 . 
     As depicted in  FIG. 38H , after being prompted to correct error indication  3814 A, the user moves her face closer to biometric sensor  3803  such that the user&#39;s face is within acceptable distance range  3812 . At  FIG. 38H , electronic device determines that error indication  3814 A no longer exists. Upon determining that error indication  3814 A no longer exists, electronic device  3800  enables biometric authentication on the device and automatically retries biometric authentication using biometric sensor  3803 . 
     In response to automatically retrying biometric authentication, electronic device  3800  displays error indication  3814 A with a shimmer effect (e.g., animating the error indication such that one or more portions of the error indication moves side to side so as produce an effect where the error indication appears to shine) to indicate that electronic device  3800  is attempting to biometrically authenticate the user again.  FIGS. 38H-38L  depict an animation of error indication  3814 A with the shimmer effect. In some examples, instead of displaying error indication  3814 A with a shimmer effect, electronic device  3800  displays (e.g., replaces display of error indication  3814 A with) authentication glyph  3810  to indicate that electronic device  3800  is attempting to biometrically authenticate the user again. Accordingly, in some examples, electronic device  3800  displays an animation of authentication glyph  3814 A morphing into lock icon  3806  instead of error indication  3814 A morphing into lock icon  3806 . 
     At  FIG. 38L , after retrying biometric authentication, electronic device  3800  successfully biometrically authenticates the user. In response to successful biometric authentication, electronic device  3800  transitions the device from a locked state to an unlocked state. While transitioning from a locked state to an unlocked state, electronic device  3800  displays an animation of error indication  3814 A morphing into lock icon  3806 , as depicted in  FIGS. 38L-38N . After displaying an animation of error indication  3814 A morphing into lock icon  3806 , electronic device  3800  displays an animation of lock icon  3806  transitioning to unlock icon  3816 , as depicted in  FIGS. 38N-38O . Unlock icon  3816  provides an indication that electronic device  3800  is in an unlocked state. Additionally, as depicted in  FIG. 38O , electronic device  3800  displays the restricted content (e.g., “Hey, is our meeting still on?”) of notification  3808  in response to biometric authentication being successful. 
     At  FIG. 38P , instead of determining that the user&#39;s face is outside acceptable distance range  3812  as discussed above with respect to  FIG. 38B , electronic device  3800  determines that biometric authentication is not available on the device. Upon determining that biometric authentication is not available, electronic device  3800  displays error indication  3814 B in  FIG. 38P , which provides an indication that biometric authentication is not currently available on the device. Biometric authentication can be unavailable for a variety of reasons, including that biometric authentication has failed more than a predefined number of times (e.g., 5, 10, 15) since the last successful authentication. 
     Due to biometric authentication being unavailable, a user must use an alternative method to authenticate the user. For example, the user can authenticate by entering a passcode at electronic device  3800 . While displaying error indication  3814 B in  FIG. 38P , electronic device  3800  receives input  3820  at error indication  3814 B. 
     At  FIG. 38Q , in response to receiving input  3820  at error indication  3814 B, electronic device  3800  displays passcode entry UI  3822 A with a plurality of entry affordances for entering a passcode (or password). 
     In some examples, instead of determining that authentication is successful as a result of retrying biometric authentication, as discussed above with respect to  FIGS. 38L-38O , electronic device  3800  determines that authentication is unsuccessful. In some examples, upon determining that authentication is unsuccessful, electronic device  3800  maintains a locked state, and displays an animation of lock icon  3806  in  FIG. 38R  alternating between different positions to simulate a “shake” effect. The shake animation provides an indication to the user that biometric authentication has failed and that electronic device  3800  remains in a locked state. 
     After determining that authentication is unsuccessful, a user can perform an action at electronic device  3800  to trigger retrying biometric authentication. At  FIG. 38S , a user triggers retrying biometric authentication by swiping up starting from a region near the bottom edge of display  3802 . Electronic device  3800  receives input  3824 , and in response, retries biometric authentication. In some examples, after retrying biometric authentication, electronic device  3800  determines that authentication is successful. In some examples, upon determining that authentication is successful as a result of retrying biometric authentication, electronic device  3800  transitions from a locked state to an unlocked state. 
     At  FIGS. 38S-38T , electronic device determines that authentication is unsuccessful as a result of retrying biometric authentication, in response to input  3824 . Upon determining that authentication is unsuccessful as a result of retrying biometric authentication, electronic device  3800  displays passcode entry UI  3822 B in  FIG. 38T . As described with respect to the processes  FIG. 37 , a user can again retry biometric authentication at passcode entry UI  3822 B by performing an upward swipe (e.g., input  3826 ). (Passcode entry UI  3822 B includes some or all of the features of passcode entry UI  3620 , including the relaxed parameters for where the upward swipe must start to initiate biometric authentication.) 
     At  FIG. 38U , electronic device determines that authentication is successful as a result of retrying biometric authentication at passcode entry UI  3822 B. Upon determining that authentication is successful, electronic device transitions from a locked state to an unlocked state, as depicted in  FIGS. 38U-38W . In some examples, at  FIG. 38U , electronic device determines that authentication is not successful as a result of retrying biometric authentication at passcode entry UI  3822 B. In some examples, upon making this determination, electronic device maintains a locked state. 
       FIGS. 38X-38AD  illustrate various error conditions that electronic device  3800  can detect while attempting to biometrically authenticate a user. Instead of displaying error indication  3814 A as described above with respect to  FIG. 38G , electronic device  3800  can display any one of the error indications described below (e.g., error indication  3814 C-I).  FIGS. 38X-38AD  also depict electronic device  3800  coaching a user (e.g., via error indication  3814 C-I) to take an action to correct the detected error condition so that electronic device  3800  can retry biometrically authenticating the user. 
     At  FIG. 38X , a user&#39;s face is positioned too close to biometric sensor  3803 . As a result, electronic device  3800  determines that the user&#39;s face is positioned outside acceptable distance range  3812  (e.g., below the minimum threshold range). Upon determining that the user&#39;s face is positioned outside acceptable distance range  3812 , electronic device  3800  displays error indication  3814 C, which prompts the user to move her face farther away from biometric sensor  3803 . Error indication  3814 C also provides an indication of the cause of the error condition (e.g., an indication that the user&#39;s face is too close to biometric sensor  3803 .) 
     At  FIG. 38Y , a user&#39;s hand is covering biometric sensor  3803 . As a result, electronic device  3800  determines that an object (e.g., a user&#39;s hand) is covering biometric sensor  3803  such that the sensor is unable to obtain any information about the user&#39;s face. Upon determining that an object is covering biometric sensor  3803 , electronic device  3800  displays error indication  3814 D, which prompts the user to move the user to move her hand away from biometric sensor  3803 . Error indication  3814 D also provides an indication of the cause of the error condition (e.g., an indication that biometric sensor  3803  is covered). 
     At  FIG. 38Z , a user is not looking at electronic device  3800 . As a result, electronic device  3800  determines that the user&#39;s eyes are not looking at the device. Upon determining that the user&#39;s eyes are not looking at the device, electronic device  3800  displays error indication  3814 E, which prompts the user to look at the device to correct the error condition. Error indication  3814 E also provides an indication of the cause of the error condition (e.g., an indication that the user is not looking at the device. 
     At  FIG. 38AA , a user&#39;s face is within field of view  3828 , but the user is wearing a hat. As a result, electronic device  3800  determines that a portion of the user&#39;s face is obscured (or occluded). For example, electronic device  3800  obtains partial information about a user&#39;s face using biometric sensor  3803 , where the partial information is below the threshold amount needed for comparison with the stored authorized credentials. Upon determining that a portion of the user&#39;s face is obscured, electronic device  3800  displays error indication  3814 F, which prompts the user to remove the hat. Error indication  3814 F also provides an indication of the cause of the error condition (e.g., an indication that a portion of the user&#39;s face is obscured). 
     At  FIG. 38AB , a user&#39;s face is outside field of view  3828  of biometric sensor  3803 . As a result, electronic device  3800  determines that the user&#39;s face is outside field of view  3828  of biometric sensor  3803 . In some examples, the user&#39;s face is outside field of view  3828  when more than a threshold portion of the face is outside the field of view. In some examples, the user&#39;s face is outside field of view  3828  when no face is detected within the field of view. Upon determining that the user&#39;s face is outside field of view  3828 , electronic device  3800  displays error indication  3814 G, which prompts the user to move her face to within field of view  3828 . Error indication  3814 G also provides an indication of the cause of the error condition (e.g., an indication that the user&#39;s face is outside field of view  3814 G). 
     At  FIG. 38AC , a user&#39;s face is within field of view  3828 , but is turned away from biometric sensor  3803 . As a result, electronic device  3800  determines that the user&#39;s face is turned away from biometric sensor  3803 . Upon determining that the user&#39;s face is turned away from biometric sensor  3803 , electronic device  3800  displays error indication  3814 H, which prompts the user to turn her face towards the sensor. Error indication  3814 H also provides an indication of the cause of the error condition (e.g., an indication that the user&#39;s face is turned away from biometric sensor  3803 ). 
     At  FIG. 38AD , a user&#39;s face is positioned appropriately within the field of view and acceptable distance range of biometric sensor  3803 . However, the lighting conditions of the environment in which the user is located are not suitable for performing biometric authentication. Specifically, the amount of light is so great that it interferes with performing biometric authentication. As a result, electronic device  3800  determines (e.g., via one or more ambient light sensors) that the amount of light exceeds a predefined threshold. Upon determining that the amount of light exceeds the threshold, electronic device  3800  displays error indication  3814 I, which prompts the user to seek improved lighting conditions with a lower amount of light. Error indication  3814 I also provides an indication of the cause of the error condition (e.g., an indication that the light conditions are not suitable for performing biometric authentication). 
       FIGS. 39A-39B  are flow diagrams illustrating a method for providing indications of error conditions during biometric authentication, in accordance with some examples. Method  3900  is performed at an electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) with a display (e.g.,  3802 ) and one or more input devices (e.g., an accelerometer (e.g.,  168 ), a touchscreen of a display (e.g.,  3802 )). In some examples, the electronic device includes one or more biometric sensors (e.g., a fingerprint sensor, a contactless biometric sensor (e.g., a biometric sensor that does not require physical contact, such as a thermal or optical facial recognition sensor), an iris scanner). In some examples, the one or more biometric sensors include one or more cameras. Some operations in method  3900  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  3900  provides an intuitive way for providing indications of error conditions during biometric authentication. The method reduces the cognitive burden on a user for performing biometric authentication, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to perform biometric authentication faster and more efficiently conserves power and increases the time between battery charges. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) receives ( 3902 ), via the one or more input devices (e.g., an accelerometer (e.g.,  168 ), a touchscreen of a display (e.g.,  3802 )), a request to perform an operation that requires authentication (e.g., biometric authentication). In some examples, the request to perform an operation that requires authentication includes a request to unlock the device (e.g., a swipe at a predefined location). In some examples, the request is triggered by lifting the device from a substantially horizontal position. 
     In response ( 3904 ) to the request to perform the operation that requires authentication (e.g., biometric authentication) and in accordance ( 3906 ) with a determination that authentication (e.g., biometric authentication) is successful, the electronic device performs the operation. In some examples, authentication is successful when a user input (e.g., data obtained from one or more biometric sensors that correspond to a biometric feature (e.g., face, finger) of a user, passcode) corresponds to (e.g., matches) an authorized credential (e.g., an enrolled fingerprint, face, or passcode). In some examples, a user input corresponds to an authorized credential when the user input matches the authorized credential. 
     In response ( 3904 ) to the request to perform the operation that requires authentication (e.g., biometric authentication) and in accordance ( 3908 ) with a determination that authentication (e.g., biometric authentication) is not successful and that a set of error condition criteria is met (e.g., an error condition exists), the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) displays ( 3910 ), on the display (e.g.,  3802 ), an indication of an error condition (e.g.,  3814 A-I) (e.g., of the set of error condition criteria) and forgoes ( 3916 ) performing the operation. The indication includes ( 3912 ) information about the cause of the error condition. In some examples, authentication is not successful when a user input (e.g., data obtained from one or more biometric sensors that correspond to a biometric feature (e.g., face, finger) of a user, passcode) does not correspond to (e.g., match) an authorized credential (e.g., an enrolled fingerprint, face, or passcode). In some examples, a user input does not correspond to an authorized credential when the user input does not match the authorized credential. In some examples, the set of error condition criteria includes only one criterion. Displaying the indication of the error condition provides the user with feedback about the current state of the device (e.g., that an error condition is preventing successful biometric authentication) and prompts the user to take further action to correct the error condition. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. Moreover, forgoing performing the operation when biometric authentication has failed and an error condition is detected enhances security and reduces the instances of multiple resource-intensive re-attempts of biometric authentication that is likely to fail due to the error condition. Providing improved security enhances the operability of the device and makes the user-device interface more efficient (e.g., by restricting unauthorized access) which, additionally, reduces power usage and improves battery life of the device by limiting the performance of restricted operations. 
     In some examples, in response ( 3904 ) to the request to perform the operation that requires authentication and in accordance ( 3926 ) with a determination that authentication (e.g., biometric authentication) is not successful and that the set of error condition criteria is not met, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) forgoes ( 3928 ) displaying, on the display (e.g.,  3802 ), the indication of the error condition and forgoes ( 3930 ) performing the operation. 
     In some examples, the indication (e.g.,  3814 A-I) of the error condition includes ( 3914 ) an indication of a user action (e.g., visible indication (e.g., graphic or text)) that can be performed to correct the error condition (e.g., for a subsequent authentication attempt). In some examples, the indication of the user action indicates how to correct the error condition for a subsequent authentication attempt. Displaying an indication of a user action that can be performed to correct the error condition provides feedback to the user as to what course of action to take so that the user can be biometrically authenticated in a subsequent authentication attempt. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. 
     In some examples, the indication (e.g.,  3814 A-I) of the error condition includes information (e.g., an indication of a user action and/or device condition, visible indication (e.g., graphic or text)) about a cause of the error condition. Displaying an indication of the cause of the error condition provides feedback to the user as to what course of action to take so that the user can be biometrically authenticated in a subsequent authentication attempt. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. 
     In some examples, the set of error condition criteria includes a requirement that is met when a biometric feature (e.g., a fingerprint, a face) of a first type (e.g., a type that corresponds to authorized biometric features) is detected using one or more biometric sensors (e.g.,  3803 ) of the electronic device. In some examples, the indication of the error condition (e.g.,  3814 A-I) is not displayed if a potentially valid biometric feature is not detected (e.g., signifying that a user is not currently engaging with the device). Forgoing displaying the indication of the error condition when no biometric feature is detected prevents potentially confusing the user, for it is likely that the user did not intend to perform biometric authentication if no biometric feature is detected. Thus, forgoing displaying the indication in this scenario makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in accordance with a determination that authentication (e.g., biometric authentication) is successful, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) forgoes displaying, on the display (e.g.,  3802 ), the indication of the error condition (e.g.,  3814 A-I). 
     In some examples, subsequent to displaying the indication of the error condition (e.g.,  3814 A-I) and in accordance with a determination that the set of error condition criteria continues to be met, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) forgoes ( 3918 ) attempting (and, optionally, disabling further attempts at) biometric authentication on the electronic device (e.g., biometric authentication functionality is not available on the device while the set of error conditions are met). In some examples, subsequent to displaying the indication of the error condition and in accordance with a determination that the set of error condition criteria is no longer met, the electronic device enables ( 3922 ) retrying biometric authentication on the electronic device (e.g., the error condition is no longer present (e.g., has been corrected (e.g., due to the user taking an action to correct the error condition))). Automatically retrying biometric authentication when the set of error condition criteria is no longer met allows the user to quickly attempt to biometrically authenticate herself without requiring that the user explicitly request biometric authentication. Performing an optimized operation when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, subsequent to displaying the indication of the error condition and in response to the determination that the set of error condition criteria is no longer met, the electronic device retries ( 3924 ) authentication (e.g., biometric authentication) (e.g., automatically retrying authentication). In some examples, retrying authentication includes attempting to match biometric information obtained by one or more biometric sensors with authorized credentials (e.g., stored data that has been authorized for use in biometric authentication). In some examples, the determination that the error condition is not met occurs subsequent to (or in response to) receiving an input to correct the error condition. In some examples, retrying authentication occurs (or only occurs) in accordance with a determination that the error condition is not met due to detecting a user input that causes the error condition to not be met. 
     In some examples, subsequent to the determination that the set of error condition criteria is no longer met (e.g., detecting that the error condition has been corrected), the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) receives, via the one or more input devices, an input (e.g.,  3824 ,  3826 ) corresponding to a request to retry authentication. In some examples, the input is a touch gesture input (e.g., tap, a swipe (e.g., an upward swipe)) or an activation of a hardware button (e.g., power button). In some examples, in response to receiving the input corresponding to the request to retry authentication, the electronic device retries authentication (e.g., biometric authentication) (e.g., automatically retrying authentication). In some examples, retrying authentication includes attempting to match biometric information obtained by one or more biometric sensors with authorized credentials (e.g., stored data that has been authorized for use in biometric authentication). In some examples, retrying authentication includes using one or more biometric sensors to obtain data of a biometric feature (e.g., face, fingerprint) of the user. 
     In some examples, displaying the indication of the error condition (e.g.,  3814 A-I) includes an animation (e.g., shimmering) indicating that an attempt to authenticate is ongoing. In some examples, the attempt to authenticate includes attempting to detect biometric information using one or more biometric sensors. Displaying a shimmering animation indicating that an attempt to authenticate is ongoing provides feedback to the user as to the current state of the device and that no further action is required at this time. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication 
     In some examples, subsequent to (or in response to) receiving the request to perform the operation that requires authentication and prior to displaying the indication of the error condition (e.g.,  3814 A-I), the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) performs authentication. In some examples, while performing authentication, electronic device  3800  displays, on the display (e.g.,  3802 ), a first indication (e.g.,  3810 ,  3814 A-I) (e.g., rings that rotate around a sphere, a user interface object that shimmers, where the user interface object includes the indication of the error condition) that the electronic device is using one or more biometric sensors (e.g.,  3803 ) of the electronic device to obtain information about a biometric feature. In some examples, displaying the indication of the error condition includes replacing the display of the first indication with the display of the indication of the error condition. Displaying an indication that biometric authentication is occurring provides the user with feedback about the current state of the device (e.g., biometric authentication is being performed) and that the user does not need to take any action at this time. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, while performing the authentication, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) displays, on the display (e.g.,  3802 ), a first lock icon (e.g.,  3806 ) (e.g., an icon indicative of the locked state of the electronic device) and a first animation that transitions from the first lock icon to the first indication. In some examples, subsequent to displaying the indication of the error condition (e.g., and in accordance with a determination that authentication is successful) and subsequent to displaying the first animation, the electronic device displays, on the display (e.g.,  3802 ), a second animation that transitions from the indication of the error condition to an unlock icon (e.g.,  3816 ) (e.g., an icon indication of the locked state of the electronic device). In some examples, the first animation and the second animation show a morphing from one object to the next object. In some examples, the second animation includes displaying a first lock icon subsequent to the indication of the error condition and prior to the unlock icon. 
     In some examples, subsequent to displaying the indication of the error condition, the electronic device displays, on the display (e.g.,  3802 ), an animation that transitions from the indication of the error condition to a second lock icon (e.g.,  3806 ) or from a second indication (e.g.,  3810 ,  3814 A-I) (e.g., rings that rotate around a sphere) that the electronic device is using one or more biometric sensors of the electronic device to obtain information about a biometric feature to the second lock icon (e.g., an icon indicative of the locked state of the electronic device). In some examples, the second lock icon is the first lock icon. In some examples, the second indication is the first indication. 
     In some examples, while retrying authentication and subsequent to displaying the indication of the error condition and in accordance with a determination that the error condition is absent, the electronic device displays, on the display, a third indication (e.g.,  3810 ,  3814 A-I) (e.g., rings that rotate around a sphere, a user interface object that shimmers, where the user interface object includes the indication of the error condition) that the electronic device is using one or more biometric sensors of the electronic device to obtain information about a biometric feature. In some examples, the third indication is the first indication. 
     In some examples, prior to displaying the indication of the error condition, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) displays, on the display (e.g.,  3802 ), a third lock icon (e.g.,  3806 ) at a location on the display (e.g., an icon indicative of the locked state of the electronic device). In some examples, the indication of the error condition (e.g.,  3814 A-I) is displayed proximate to (e.g., near, adjacent to, at, within a predetermined distance of) the location on the display. In some examples, the third lock icon is the first lock icon and/or the second lock icon. 
     In some examples, when the electronic device is in a locked state while receiving the request to perform the operation that requires authentication and in accordance with the determination that authentication is successful, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) transitions from the locked state to an unlocked state. In some examples, the operation that requires authentication is transitioning the electronic device from a locked state to an unlocked state. In some examples, when the electronic device is in a locked state while receiving the request to perform the operation that requires authentication and in accordance with the determination that authentication is not successful, the electronic device maintains the locked state. Maintaining the device in the locked state when authentication is unsuccessful enhances device security by preventing fraudulent and/or unauthorized access to the device. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, when the electronic device is in a locked state while receiving the request to perform the operation that requires authentication and in accordance with the determination that authentication is not successful, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) maintains the locked state and retries authentication (e.g., biometric authentication) (e.g., automatically retrying authentication). In some examples, retrying authentication includes attempting to obtain information about a biometric feature (e.g., face, fingerprint) using one or more biometric sensors of the electronic device. In some examples, retrying authentication includes attempting to match biometric information obtained by one or more biometric sensors with authorized credentials (e.g., stored data that has been authorized for use in biometric authentication). In some examples, after retrying authentication and in accordance with a determination that authentication resulting from retrying authentication is successful, the electronic device transitions from the locked state to an unlocked state. In some examples, after retrying authentication and in accordance with a determination that authentication resulting from retrying authentication is not successful, the electronic device maintains the locked state. 
     In some examples, subsequent to (or in response to) receiving the request to perform the operation that requires authentication, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) attempts authentication (e.g., biometric authentication). In some examples, while attempting authentication, the electronic device displays, on the display (e.g.,  3802 ), a third indication (e.g.,  3810 ,  3814 A-I) (e.g., rings that rotate around a sphere) that the electronic device is using one or more biometric sensors of the electronic device to obtain information about a biometric feature (e.g., face, fingerprint). In some examples, the indication is a scanning animation. In some examples, the third indication is the first indication and/or the second indication. In some examples, while retrying authentication, the electronic device maintains display of the third indication on the display (e.g.,  3802 ). 
     In some examples, in accordance with the determination that authentication resulting from retrying authentication is not successful, the electronic device displays, on the display (e.g.,  3802 ), an animation with a lock icon (e.g.,  3806 ) (e.g., an icon indicative of the locked state of the electronic device) alternating between a first position and a second position, the second position being different from the first position. In some examples, the animation with the lock icon is an animation of the lock icon shaking (e.g., side to side, rotating back and forth). In some examples, the electronic device displays an animation involving the lock icon to indicate that biometric authentication has failed. In some examples, a tactile output is provided in combination with the shaking lock icon. In some examples, no tactile output is provided. In some examples, in accordance with a determination that the biometric information captured using the one or more biometric sensors does not correspond to or does not match the authorization credentials, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) maintains the locked state of the electronic device. Displaying an animation of the lock icon shaking provides the user with feedback about the current state of the device (e.g., that biometric authentication has failed) and prompts the user to take further action. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) includes a biometric sensor (e.g.,  3803 ) and the set of error condition criteria includes one or more of the following error condition criterions:
         A distance of the biometric feature from the biometric sensor exceeds a first predetermined threshold distance (e.g., the biometric feature (e.g., face) is too far from the biometric sensor) or exceeds the maximum of a distance range (e.g.,  3812 ). In some examples, exceeding the first predetermined threshold or the maximum of a distance range is highly correlated with degradation or reduced accuracy of the information about the biometric feature obtained by the biometric sensor). In some examples, the user can correct this error condition by moving the user&#39;s face closer to the biometric sensor.   A distance of the biometric feature from the biometric sensor is below a second predetermined threshold distance (e.g., the biometric feature (e.g., face) is too close to the biometric sensor) or falls below the minimum of a distance range (e.g.,  3812 ). In some examples, falling below the second predetermined threshold or the minimum of a distance range is highly correlated with degradation or reduced accuracy of the information about the biometric feature obtained by the biometric sensor. In some examples, the user can correct this error condition by moving the user&#39;s face farther away from the biometric sensor.   The biometric sensor (e.g.,  3803 ) is occluded (e.g., partially occluded, fully occluded, occluded to a degree sufficient to inhibit operation of the sensor) (e.g., occluded by a portion of the user (e.g., a hand), while interacting with the electronic device). In some examples, the user can correct this error condition by moving the user&#39;s hand away from the biometric sensor.   A sub-portion of a detected biometric feature (e.g., eyes of a detected face) is not oriented towards the biometric sensor (e.g., one or more eyes are not focused on the electronic device (e.g., biometric sensor)). In some examples, the user can correct this error condition by opening the user&#39;s eyes or looking at the electronic device (e.g., biometric sensor). —At least a portion of the detected biometric feature is occluded (e.g., partially occluded, fully occluded, occluded to a degree sufficient to result in incomplete information about the biometric feature). In some examples, the user can correct this error condition by removing the accessory (e.g., sunglasses) or article of clothing (e.g., scarf, hat) that is blocking the user&#39;s face.   No biometric feature is detected within a field of view (e.g.,  3828 ) of the biometric sensor.   A pose (e.g., an orientation with respect to the biometric sensor) of the detected biometric feature exceeds a threshold range (e.g., the biometric feature (e.g., face) is turned away from the biometric sensor). In some examples, exceeding the threshold range is highly correlated with degradation or reduced accuracy of the information about the biometric feature obtained by the biometric sensor. In some examples, the user can correct this error condition by turning the user&#39;s face toward the electronic device (e.g., biometric sensor).   The electronic device detects (e.g., via one or more ambient light sensors) an amount of light (e.g., ambient light) that exceeds a predetermined light threshold (e.g., exceeding the predetermined light threshold is highly correlated with degradation or reduced accuracy of the information about the biometric feature obtained by the biometric sensor). In some examples, the user can correct this error condition by turning the user&#39;s back towards the sun so as to reduce the amount of light detected by the electronic device or move to a new location that has less ambient light (e.g., indoors).       

     In some examples, the set of error condition criteria can be a first subset of the error conditions listed above. For example, the first subset can include one or more error condition criterion selected from the group consisting of: the distance of the biometric feature exceeds a first predetermined threshold distance, the distance of the biometric feature is below a second predetermined threshold distance, the biometric feature is out of the field of view of the biometric sensor, and the pose of the biometric feature exceeds a threshold range. The first subset is focused on guiding the user to correct error conditions involving the positioning and/or orientation of the face. As a further example, a second subset can include one or more error condition criterion selected from the group consisting of: the biometric sensor is occluded, and no biometric feature is detected within a field of view of the biometric sensor. The second subset is focused on guiding the user to correct error conditions where the biometric sensor is unable to obtain any information about the biometric feature of the user. For another example, a third subset can include one or more error condition criterion selected from the group consisting of: the pose of the detected biometric feature exceeds a threshold range and the biometric sensor is occluded. The third subset is focused on the error conditions that are likely to occur for devices of a certain form factor/size (e.g., a tablet device (e.g., iPad)). 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) includes a biometric sensor (e.g.,  3803 ) at a portion (e.g., a location) of the electronic device (e.g., a portion that is not on the display). In some examples, in response to the request to perform the operation that requires authentication, the electronic device displays, on the display (e.g.,  3802 ), a progress indicator (e.g.,  3814 A-I) proximate to (e.g., adjacent to, near, within a predetermined distance of) the portion of the electronic device, the progress indicator including the indication of the error condition. Displaying the progress indicator near the biometric sensor provides the user with feedback as to the association of the biometric sensor with the processes occurring at the device (e.g., attempted authentication). Specifically, the user becomes aware of the biometric sensor during biometric authentication such that the user is less likely to perform an action that interferes with the biometric sensor or alternatively, the user is prompted to take corrective action. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the indication of the error condition (e.g.,  3814 B) includes an indication that biometric authentication is currently not enabled on the electronic device in accordance with a determination that biometric authentication is currently not enabled on the electronic device. In some examples, biometric authentication can become unavailable (or not enabled on the electronic device) when one or more of the following conditions have been met: the electronic device has not been successfully authenticated since being turned on or restarted; the electronic device has not been unlocked for more than a predetermined amount of time (e.g., 48 hours); the passcode has not been used to unlock the device for more than a predetermined amount of time (e.g., 156 hours); biometric authentication using a biometric feature (e.g., face, fingerprint) has not been used to unlock device for more than predetermined amount of time (e.g., 4 hours); the electronic device has received a remote lock command; biometric authentication has failed more than a predetermined number of times (e.g., 5, 10, 15) since the last successful authentication with the device; the electronic device has received a power off and/or emergency SOS command, and an explicit request by the user to disable biometric authentication has been detected. Displaying an indication that biometric authentication is currently not enabled provides feedback to the user of the current state of the device and prompts the user to pursue an alternative method to authenticate herself. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the indication that biometric authentication is currently not enabled includes an affordance (e.g.,  3814 B) (e.g., the indication is an affordance). In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) receives an input (e.g.,  3820 ) corresponding to the affordance and in response to receiving the input corresponding to the affordance, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) displays, on the display (e.g.,  3802 ), a credential entry user interface (e.g.,  3822 A) with a plurality of character entry keys. In some examples, the credential entry user interface includes a virtual keypad or virtual keyboard. In some examples, the virtual keypad or virtual keyboard includes a plurality of character entry keys. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  3800 ) detects a condition that triggers attempting authentication (e.g., biometric authentication). In some examples, the request to perform an operation that requires authentication includes a request to unlock the device (e.g., a swipe at a predefined location). In some examples, in response to detecting the condition that triggers attempting authentication (e.g., biometric authentication) and in accordance with a determination that the condition corresponds to an alert (e.g.,  3808 ) generated by the device without user input directed to the device (e.g., based on the satisfaction of criteria other than detection of user input) while a biometric feature is available for detection by the one or more biometric sensors (e.g., a face is detected in the field of view of one or more face detection sensors such as a depth camera), the electronic device displays a fifth indication (e.g.,  3810 ) (e.g., rings that rotate around a sphere) that the electronic device is using the one or more biometric sensors of the electronic device to obtain information about a biometric feature. In some examples, in accordance with a determination that the condition corresponds to an alert generated by the device without user input directed to the device (e.g., based on the satisfaction of criteria other than detection of user input) while a biometric feature is not available for detection by the one or more biometric sensors (e.g., no face is detected in the field of view of one or more face detection sensors such as a depth camera), the electronic device forgoes displaying the fifth indication (e.g., rings that rotate around a sphere) that the electronic device is using the one or more biometric sensors of the electronic device to obtain information about a biometric feature. In some examples, in accordance with a determination that the condition corresponds to a user input directed to the device (e.g., a request that is not associated with a notification; a request that is a touch gesture input (e.g., tap, a swipe (e.g.,  3824 ) (e.g., an upward swipe) or an activation of a hardware button (e.g., power button) or sensor data indicative of movement (e.g., lifting) of the device)), the electronic device displays the fifth indication that the electronic device is using one or more biometric sensors of the electronic device to obtain information about a biometric feature (e.g., without regard to whether or not the biometric feature is available for detection by the one or more biometric sensors). Forgoing displaying the indication when no face is detected prevents potentially confusing the user, for it is likely that the user does not intend to initiate biometric authentication if no biometric feature is detected. Thus, forgoing displaying the indication in this scenario makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     Note that details of the processes described above with respect to method  3900  (e.g.,  FIGS. 39A-39B ) are also applicable in an analogous manner to the methods described below/above. For example, method  3700 , method  4100 , and/or method  4300  optionally include one or more of the characteristics of the various methods described above with reference to method  3900 . For example, the error indications (e.g.,  3814 A-I) as described with respect to method  3900  can be used to provide indications of error conditions during biometric authentication that is performed in processes described with respect to method  3700  and method  4100 . For brevity, these details are not repeated below. 
       FIGS. 40A-40U  illustrate exemplary user interfaces for providing indications about the biometric sensor during biometric authentication, in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIGS. 41A-41C . 
       FIG. 40A  illustrates electronic device  4000  (e.g., portable multifunction device  100 , device  300 , device  500 ). In the exemplary examples illustrated in  FIGS. 40A-40U , electronic device  4000  is a tablet computer. In other examples, electronic device  4000  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  4000  includes display  4002 , one or more input devices (e.g., touchscreen of display  4002 , button  4004 , and a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In  FIG. 40A , the electronic device includes biometric sensor  4003 . In some examples, the biometric sensor is one or more biometric sensors that can include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, biometric sensor  4003  is biometric sensor  703 . In some examples, the one or more biometric sensors include one or more fingerprint sensors (e.g., a fingerprint sensor integrated into a button). In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     At  FIG. 40A , a user wishes to purchase goods using payment information stored on electronic device  4000 . As depicted in  FIG. 40A , electronic device  4000  is in a split screen (e.g., multitasking) mode. While in the split screen mode, electronic device  4000  concurrently displays app store user interface (UI)  4006  in left region  4007  of display  4002  and browser UI  4008  in right region  4009  of display  4002 . While concurrently displaying app store UI  4006  and browser UI  4008 , electronic device  4000  receives input  4010  at purchase affordance  4012 . 
     At  FIG. 40B , in response to receiving input  4010  at purchase affordance  4012 , electronic device  4000  swaps the applications being displayed in left region  4007  and right region  4009  of display  4002 . Specifically, electronic device  4000  displays browser UI  4008  in left region  4007 , and displays app store UI  4006  in right region  4009 . Electronic device  4000  swaps the applications in order to place the application associated with the goods being purchased in the region that is closer to biometric sensor  4003 . By placing browser UI  4008  in left region  4007 , electronic device  4000  provides an indication to the user of the location of biometric sensor  4003 , which is used to authenticate the user prior to authorizing payment for purchasing the goods. As shown in  FIG. 40B , swapping the applications also places the application associated with the goods being purchased in the region that is closer to button  4004 . In some examples, when the button  4004  and the biometric sensor  4003  are not in close proximity (e.g., on the same side), electronic device  4000  swaps applications, when necessary, to place the application associated with the goods being purchased in the region that is closer to the biometric sensor  4003 . In some examples, when button  4004  and biometric sensor  4003  are not in close proximity (e.g., on the same side), electronic device  4000  swaps applications, when necessary, to place the application associated with the goods being purchased in the region that is closer to the button  4004 . 
     Additionally, as depicted in  FIG. 40B , in response to receiving input  4010  at purchase affordance  4012 , electronic device  4000  darkens browser UI  4008  while darkening app store UI  4006  to a greater degree than that of browser UI  4008 . By darkening browser UI  4008  less than app store UI  4006 , electronic device  4000  indicates to the user which application is associated with pay sheet interface  4014  and the goods the user wishes to purchase. 
     Moreover, in response to receiving input  4010  at purchase affordance  4012 , electronic device  4000  concurrently displays pay sheet interface  4014  with information about the goods being purchased and prompt  4016  to prompt the user to double-click button  4004  to initiate a process for authorizing payment for the goods. Further in response to receiving input  4010  at purchase affordance  4012 , electronic device  4000  displays dynamic indication  4018  to emphasize the location of button  4004 . While displaying pay sheet interface  4014 , electronic device receives input  4020  at button  4004  (e.g., double-press of button  4004 ). In some examples, prompt  4016  includes some or all of the features of prompt  2416 . In some examples, dynamic indication  4018  includes some or all of the features of dynamic indication  2418 . In some examples, pay sheet interface  1014  includes the name of the application to which it corresponds (e.g., the name of the application from which the user initiated the process for authorizing payment). 
     At  FIG. 40C , in response to receiving input  4020  at button  4004 , electronic device  4000  initiates a process for authorizing payment for the goods. Authorizing payment for the goods requires successfully authenticating the user. As a result, in response to receiving input  4020 , electronic device  4000  initiates biometric authentication using biometric sensor  4003 . After initiating biometric authentication, electronic device  4000  displays face glyph  4022 , which provides an indication that electronic device  4000  is attempting to biometrically authenticate the user (e.g., attempting to obtain biometric information about the user using biometric sensor  4003 ). In some examples, face glyph  4022  includes some or all of the features of glyph  2468  of  FIG. 24F . In some examples, in response to receiving input  4020  at button  4004 , electronic device displays an animation of face glyph  4022  moving from the location of prompt  4016  to the location of face glyph  4022 , as depicted in  FIG. 40C . In some examples, the animation is such that face glyph  4022  appears to slide out of prompt  4016 . 
     At  FIG. 40D , after displaying face glyph  4022 , electronic device transitions to displaying authentication glyph  4024 , which provides an indication that electronic device  4000  is attempting to biometrically authenticate the user (e.g., continuing to try to obtain biometric information, attempting to match obtained information with stored authorized credentials). Authentication glyph  4024  includes a plurality of rings that rotate spherically. In some examples, authentication glyph  4024  includes some or all of the features of one or more rings  2470  of  FIG. 24G . 
     While displaying authentication glyph  4024 , electronic device  4000  detects that an error condition exists (e.g., a condition that prevents biometric sensor  4003  from obtaining sufficient information about the user&#39;s face). Specifically, electronic device  4000  detects that biometric sensor  4003  is covered by a physical object (e.g., the user&#39;s hand)). In some examples, electronic device  4000  does not detect an error condition, and is able to obtain sufficient information about the user&#39;s face. In some examples, after obtaining sufficient information about the user&#39;s face and while displaying authentication glyph  4024 , electronic device  4000  determines whether the obtained information satisfies biometric authentication criteria (e.g., determines whether the obtained biometric information matches, within a threshold, a biometric template associated with the user (e.g., stored authorized credentials)). In some examples, upon determining that biometric authentication is successful (e.g., biometric authentication criteria is satisfied), electronic device  4000  transitions to an unlocked state. 
     At  FIG. 40E , in response to detecting that an error condition exists, electronic device  4000  displays error indication  4026  at a location at the top of display  4002  (e.g., with respect to the ground, with respect to the user). Error indication  4026  provides an indication of the error condition that currently exists. Further in response to detecting that an error conditions exists, electronic device  4000  displays error icon  4028  at a location of display  4002  that is adjacent to biometric sensor  4003 , thereby providing an indication of the location of biometric sensor  4003 . By providing an indication of the location of biometric sensor  4003 , error icon  4028  suggests to the user the cause of the error condition. In some examples, in response to detecting that an error condition exists, electronic device  4000  displays error indication  4026  at a location adjacent to biometric sensor  4003 . In some examples, error indication  4026  includes some or all of the features of error indication  3814 A, including a shimmer effect. 
     At  FIG. 40F , further in response to detecting that an error condition exists, electronic  4000  displays an animation of pay sheet interface  4014  moving from its initial location in  FIG. 40E  to the location in  FIG. 40F , which is closer to biometric sensor  4003 . By moving pay sheet interface towards biometric sensor  4003 , electronic device  4000  indicates to the user the existence of error icon  4028  in addition to indicating the location of biometric sensor  4003  (and thus suggesting to the user the cause of the error condition). 
     In some examples, error icon  4028  is displayed at different location of display  4002  depending on the positioning of the user&#39;s hand on display  4002 . As illustrated in  FIG. 40F , the user&#39;s hand is covering a portion of display  4002  that is adjacent to biometric sensor  4003 . While the user&#39;s hand is in contact with display  4002 , electronic device  4000  detects an input as a result of the contact from the user&#39;s hand. In response to detecting this input, electronic device  4000  displays error icon  4028  at a location at which the input is not detected. As another example, in  FIG. 40G , the user&#39;s hand is covering less of display  4002  than the user&#39;s hand in  FIG. 40F . In some examples, in response to detecting the input of the user&#39;s hand in  FIG. 40G , electronic device  4000  displays error icon  4028  at a location that is different from the location in  FIG. 40F , where the location in  FIG. 40G  is closer to biometric sensor  4003  than that of  FIG. 40F . As yet another example, in  FIG. 40H , the user&#39;s hand is covering a large portion of the upper-left side of display  4002 . In some examples, in response to detecting the input of the user&#39;s hand in  FIG. 40H , electronic device  4000  displays error icon  4028  at a location that is different from the locations in  FIGS. 40F-40G . Specifically, in some examples, electronic device  4000  displays error icon  4028  at a location that is close to (or substantially near) biometric sensor  4003  without being at a location where the input of the user&#39;s hand is detected. 
     At  FIG. 40I , the user removes her hand such that it no longer covers biometric sensor  4003 . While displaying error icon  4028  and error icon  4028 , electronic device  4000  detects that the error condition no longer exists. 
     At  FIG. 40J , in response to detecting that the error condition no longer exists, electronic device  4000  automatically retries biometric authentication. While retrying biometric authentication, electronic device  4000  displays authentication glyph  4024 . While displaying authentication glyph  4024 , electronic device  4000  attempts to biometrically authenticate the user. Specifically, electronic device  4000  obtains information about the user&#39;s face using biometric sensor  4003 , and determines whether biometric authentication is successful (e.g., the obtained information matches stored authorized credentials). 
     While retrying biometric authentication, electronic device  4000  determines that biometric authentication is successful. At  FIG. 40K , upon determining biometric authentication is successful, electronic device  4000  displays success glyph  4030 , which provides an indication that biometric authentication was successful. In some examples, success glyph  4030  includes some or all of the features of glyph  2474 . 
     At  FIG. 40L , further in response to determining that biometric authentication is successful, electronic device  4000  displays processing indicator  4032 , which provides an indication that the payment transaction is being processed (e.g., electronic device  4000  is transmitting payment information (e.g., credentials) to an external device (e.g., server) to authorize payment). In some examples, processing indicator  4032  has some or all of the features of processing indication  2476 . 
     At  FIG. 40M , upon receiving an indication that payment has been completed (e.g., authorized), electronic device  4000  displays completed indication  4034 , which provides an indication that payment has been completed. In some examples, completed indication  4034  has some or all of the features of completed indication  2478  of  FIG. 24AR . 
       FIGS. 40N-40S  illustrate a technique for displaying error indication  4026  and error icon  4028  when error indication  4026  and error icon  4028  are to be displayed in approximately the same location. At  FIG. 40N , a user wishes to unlock the device to access restricted content (e.g., a home screen, a most recently used application).  FIG. 40N  depicts electronic device  4000  in a portrait orientation with respect to the ground, where a user is covering biometric sensor  4003  with her hand. Additionally, electronic device  4000  displays locked state UI  4036  with lock icon  4038 . Lock icon  4038  provides an indication that electronic device  4000  is in a locked state. 
     While displaying locked state UI  4036 , electronic device  4000  receives a request to unlock the device. For example, electronic device  4000  detects the user lifting the device from a substantially horizontal position. 
     At  FIG. 40O , in response to receiving the request to unlock the device, electronic device  4000  attempts to biometrically authenticate the user. While attempting to biometrically authenticate the user, electronic device  4000  displays authentication glyph  4024 . Additionally, while attempting to biometrically authenticate the user, electronic device  4000  detects that an error condition exists (e.g., a condition that prevents biometric sensor  4003  from obtaining sufficient information about the user&#39;s face). Specifically, electronic device  4000  detects that biometric sensor  4003  is covered by a physical object (e.g., the user&#39;s hand)). 
     At  FIG. 40P , in response to detecting that an error condition exists, electronic device  4000  displays error icon  4028  at a location of display  4002  that is near biometric sensor  4003  (e.g., at the top of display  4002 ). Further in response to detecting that an error condition exists, electronic device  4000  determines that error indication  4026  is to be displayed at approximately the same location as error icon  4028 . Upon determining that error indication  4026  is to be displayed at approximately the same location, electronic device  4000  does not immediately display error indication  4028 , and instead displays error indication  4026  as part of an animation that transitions from error icon  4028  to error indication  4026  to lock icon  4038 , as described below with respect to  FIGS. 40Q-40R . 
     At  FIG. 40Q , after displaying error icon  4028 , electronic device  4000  displays (e.g., replaces display of error icon  4028  with) error indication  4026 , which as discussed above, provides an indication of the cause of the error condition. 
     While displaying error indication  4026 , the user removes her hand from biometric sensor  4003  such that it no longer covers biometric sensor  4003 . In response to detecting that the error condition no longer exists, electronic device  4000  automatically retries biometric authentication. 
     At  FIGS. 40R-40S , upon determining that authentication is successful as a result of retrying biometric authentication, electronic device  4000  transitions from a locked state to an unlocked state. Specifically, electronic device  4000  displays (e.g., replaces display of error indication  4026  with) an animation of lock icon  4038  transitioning to unlock icon  4040 , which provides an indication to the user that electronic device  4000  has transitioned to an unlocked state. In some examples, instead of successful biometric authentication, electronic device  4000  determines that authentication is unsuccessful as a result of retrying biometric authentication. In some examples, upon determining that authentication is unsuccessful, electronic device  4000  displays a passcode entry UI with an affordance which, when activated, triggers retrying biometric authentication. In some examples, while retrying biometric authentication, electronic device  4000  darkens all portions of display  4002  except for the user interface associated with retrying biometric authentication. 
       FIG. 40T  illustrates a technique for displaying error icon  4028  when error icon  4028  is to be displayed at approximately the same location as one of the notifications being displayed (e.g.,  4044 A-D). In some examples, a user wishes to view the restricted content of one or more of the notifications (e.g.,  4044 A-D) that are displayed while electronic device  4000  is in a locked state. As depicted in  FIG. 40T , a user is covering biometric sensor  4003  with her hand when the electronic device is a portrait orientation, where biometric sensor  4003  is located near the bottom of the device. In some examples, while attempting to biometrically authenticate a user to access the restricted content of the notifications, electronic device  4000  detects that an error condition exists as a result of the user covering biometric sensor  4003  with her hand. In response to detecting that an error condition exists, electronic device  4000  determines that error icon  4028  is to be displayed at approximately the same location as one of the notifications (e.g.,  4044 A-D). Upon making this determination and in response to detecting that the error condition exists, electronic device  4000  displays UI element  4042  (e.g., a background) concurrently with error icon  4028  to provide a background on which to overlay the display of error icon  4028 . As depicted in  FIG. 40T , UI element  4042  is opaque such that the notification on which error icon  4028  is overlaid (e.g.,  4042 D) is not visible to the user. In some examples, UI element  4042  is transparent such that the notification on which error icon  4028  is overlaid is visible to the user. 
       FIG. 40T  also illustrates a technique for hiding unlock indication  4044  of  FIG. 40U  when error icon  4028  is to be displayed at approximately the same location as unlock indication  4044 . In some examples, electronic device  4000  displays unlock indication  4044 , which provides an indication of an approximate location on display  4002  from which a user can start an upward swipe to initiate biometric authentication. In some examples, while displaying unlock indication  4044 , electronic device  4000  detects that an error condition exists as a result of the user covering biometric sensor  4003  with her hand. In some examples, in response to detecting that an error condition exists, electronic device  4000  determines that error icon  4028  is to be displayed at approximately the same location as unlock indication  4044 . In some examples, upon making this determination and in response to detecting that the error condition exists, electronic device  4000  ceases to display unlock indication  4044 , and displays error icon  4028  at approximately the same location at which unlock indication  4044  was displayed. 
     While displaying error icon  4028 , electronic device  4000  detects that the error condition no longer exists (e.g., due to the user removing her hand from biometric sensor  4003 ). As depicted in  FIG. 40U , the user has removed her hand from biometric sensor  4003 . At  FIG. 40U , upon detecting that the error condition no longer exists, electronic device  4000  ceases to display error icon  4028 , and re-displays unlock indication  4044  at the location at which it was previously displayed. 
       FIGS. 41A-41C  are flow diagrams illustrating a method for providing indications about the biometric sensor during biometric authentication, in accordance with some examples. Method  4100  is performed at an electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) with a display (e.g.,  4002 ) and a biometric sensor (e.g.,  4003 ) (e.g., a first biometric sensor of a device with a plurality of biometric sensors) (e.g., a fingerprint sensor, a contactless biometric sensor (e.g., a biometric sensor that does not require physical contact, such as a thermal or optical facial recognition sensor), an iris scanner) at a first portion of the electronic device (e.g., a portion that is not a part of the display). In some examples, the biometric sensor includes one or more cameras. Some operations in method  4100  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  4100  provides an intuitive way for providing indications about the biometric sensor during biometric authentication. The method reduces the cognitive burden on a user for performing biometric authentication, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to perform biometric authentication faster and more efficiently conserves power and increases the time between battery charges. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) detects ( 4102 ) (e.g., detects in response to a request to perform an operation that requires authentication) the existence of an error condition that prevents the biometric sensor from obtaining biometric information about a user of the device (e.g., a contactless biometric sensor such as a thermal or optical facial recognition sensor) is occluded (e.g., partially occluded, fully occluded, occluded to a degree sufficient to inhibit operation of the sensor) (e.g., occluded by a portion of the user (e.g., a hand), while interacting with the electronic device). 
     In response ( 4104 ) to detecting the existence of the error condition, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) displays, on the display (e.g.,  4002 ), an error indication (e.g.,  4028 ) (e.g., a graphical icon). In some examples, the error indication includes text (e.g., indicating that the sensor is occluded. In some examples, the error indication does not include text. The error indication is displayed ( 4106 ) at a location that is proximate to the first portion of the electronic device. In some examples, the location is at or near the portion of the display that is closest to the location of the biometric sensor (e.g.,  4003 ). Displaying the error indication provides the user with feedback about the current state of the device (e.g., that an error condition is preventing successful biometric authentication) and prompts the user to take further action to correct the error condition. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. Displaying the error indication near the biometric sensor provides the user with feedback as to the association of the biometric sensor with the processes occurring at the device (e.g., attempted authentication). Specifically, the user becomes aware of the biometric sensor during biometric authentication such that the user is less likely to perform an action that interferes with the biometric sensor or alternatively, the user is prompted to take corrective action. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the error indication (e.g.,  4028 ) includes ( 4108 ) a biometric sensor occluded icon and a reticle, the error indication providing an indication that the biometric sensor is occluded. (ISE, the error indication is associated with the electronic device performing biometric authentication (e.g., using the biometric sensor to obtain biometric information about a biometric feature (e.g., face, fingerprint).) Providing an indication that the biometric sensor is occluded provides the user with feedback about the current state of the device (e.g., that the biometric sensor is occluded) and prompts the user to take further action to correct the error condition. Providing improved feedback with instructions on proper movements of the biometric feature therefore enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance ( 4110 ) with a determination that a user interface of the electronic device is in a first orientation relative to the biometric sensor, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) displays the error indication at a first location in the user interface that is proximate to (e.g., adjacent to, near to, within a predetermined distance of) the first portion of the electronic device. 
     In accordance ( 4112 ) with a determination that the user interface of the electronic device is in a second orientation relative to the biometric sensor, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) displays the error indication (e.g.,  4028 ) at a second location in the user interface that is proximate to (e.g., adjacent to, near to, within a predetermined distance of) the first portion of the electronic device, the first orientation being different from the second orientation. 
     In some examples, while attempting ( 4114 ) to obtain biometric information using the biometric sensor (e.g.,  4003 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) displays ( 4116 ), on the display (e.g.,  4002 ), a first progress indicator (e.g.,  4024 ,  4026 ,  4038 ,  4040 ). In some examples, the first progress indicator provides an indication of the current state of the electronic device (e.g., locked state, unlocked state, performing biometric authentication, error state, error condition). In some examples, in accordance ( 4118 ) with a determination that the user interface (e.g.,  4006 ,  4008 ) of the electronic device is in a third orientation relative to the biometric sensor, the user interface in the third orientation having a first top side, the electronic device displays the first progress indicator proximate to (e.g., adjacent to, near to, within a predetermined distance of) the first top side of the user interface in the third orientation. In some examples, in accordance ( 4120 ) with a determination that the user interface of the electronic device is in a fourth orientation relative to the biometric sensor, the user interface in the fourth orientation having a second top side, the electronic device displays the first progress indicator proximate to (e.g., adjacent to, near to, within a predetermined distance of) the second top side of the user interface in the fourth orientation, the third orientation being different from the fourth orientation. In some examples, the first progress indicator is displayed on the display at a location that is closest to or proximate to (e.g., adjacent to, near to, within a predetermined distance of) the biometric sensor. Displaying the first progress indicator near the top of the display regardless of orientation ensures that the user is more likely to be aware of the provided feedback to the user (e.g., the progress indicator). Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) displays, on the display (e.g.,  4002 ), a second progress indicator (e.g.,  4024 ,  4026 ,  4038 ,  4040 ) of the electronic device. In some examples, the second progress indicator provides an indication of the current state of the electronic device (e.g., locked state, unlocked state, performing biometric authentication, error state). In some examples, the first progress indicator is the second progress indicator. In some examples, the second progress indicator is an animation with a first portion (e.g., an indication that the electronic device is performing biometric authenticating using the biometric sensor (e.g.,  4024 ) (e.g., rotating rings)) and a second portion (e.g., an indication of an error condition or error state (e.g.,  4026 ), an indication of the current lock or unlock state of the electronic device (e.g., lock icon (e.g.,  4038 ), unlock icon (e.g.,  4040 ))) that is different from the first portion. In some examples, in accordance with a determination that the second progress indicator is displayed at the location that is proximate to the first portion of the electronic device, the electronic device displays the error indication (e.g.,  4028 ) as part of the animation subsequent to the first portion and prior to the second portion. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) displays, on the display (e.g.,  4002 ), a home affordance (e.g.,  4044 ) (e.g., an indication of a location of a gesture that when performed, results in displaying a home screen such as a swipe up gesture from an edge of the display or a tap gesture on the affordance) at a third location (e.g., a location proximate to a side (e.g., bottom side) of the user interface) in the user interface. In some examples, in accordance with a determination that the error indication (e.g.,  4028 ) is displayed at the third location, the electronic device ceases to display the home affordance (e.g.,  4044 ) while displaying the error indication at the third location. Ceasing display of the home affordance while displaying an error indication allows the user to quickly realize the home affordance is not accessible because there is an error and prompts the user to take further action to correct the error condition. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. 
     In some examples, after ceasing to display the home affordance (e.g.,  4044 ), the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) detects a correction of the error condition that prevents the biometric sensor (e.g.,  4003 ) from obtaining biometric information about the user of the device. In some examples, the electronic device detects the absence of the error condition subsequent to displaying the error indication (e.g.,  4028 ) at the third location. In some examples, in response to detecting the correction of the error condition, the electronic device displays, on the display (e.g.,  4002 ), the home affordance at the third location in the user interface (e.g., and ceases to display the error indication (e.g.,  4028 )). 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) detects an input (e.g., palm, finger) at the location that is proximate to (e.g., adjacent to, near to, within a predetermined distance of) the first portion of the electronic device. In some examples, in response to detecting the input at the location that is proximate to the first portion of the electronic device, the electronic device displays, on the display, the error indication (e.g.,  4028 ) at a different location. In some examples, the different location is a location at which the input is not detected. In some examples, prior to displaying the error indication at the new location, the electronic device determines the different location based on the location of the input with respect to the display. In some examples, the different location is proximate to the location that is proximate to the first portion of the electronic device. In some examples, the error indication is moved to the different location after being initially displayed at a first location that is proximate to the first portion of the electronic device. In some examples, the error indication is initially displayed at a location selected so as to be away from any regions of the display that are known to be occluded (e.g., occluded by a detected touch input). Displaying the error indication at a different location depending on the location of the input (e.g., a user&#39;s hand) provides the user with feedback about the current state of the device (e.g., that an error condition is preventing successful biometric authentication) and prompts the user to take further action to correct the error condition. Further, by adjusting the location, the device ensures that the error indication is visible to the user and thus, the user is more likely to take corrective action at the device. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) displays, on the display (e.g.,  4002 ), a first transaction interface (e.g.,  4014 ) (e.g., a transaction (or payment) interface that is separate from (or overlaid on top of) the user interface and includes transaction information such as a credit card number, billing address, etc.) at a position that is proximate to (e.g., adjacent to, near to, within a predetermined distance of) the first portion of the electronic device. In some examples, the first transaction interface is displayed in response to receiving an input (e.g.,  4010 ) corresponding to an affordance (e.g.,  4012 ) of the user interface (e.g.,  4008 ) (e.g., an affordance for making a payment or completing a transaction). 
     In some examples, displaying the first transaction interface (e.g.,  4014 ) includes displaying an animation of the first transaction interface transitioning (e.g., translating) from an initial position that is substantially centered with respect to the display to the position that is proximate to the first portion of the electronic device. In some examples, the animation includes displaying (e.g., maintaining the display of) the first transaction interface while the first transaction interface transitions (e.g., translates) from the initial position to the position that is proximate to the first portion of the electronic device. In some examples, the animation includes a visual effect where the first transaction interface appears to float while transitioning. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) displays, on the display (e.g.,  4002 ), a prompt (e.g.,  4016 ) to provide one or more activations of a hardware button (e.g.,  4004 ) of the electronic device. In some examples, the electronic device prompts the user by displaying “double click for Apple Pay”. In some examples, the prompt is displayed adjacent to the button. In some examples, the prompt is displayed when the device is displaying a transaction user interface region (e.g.,  4014 ) but without receiving any indication that a transaction terminal is nearby and is requesting transaction credentials (e.g., the prompt to provide the one or more activations of the button are displayed before the device as been placed in an NFC field of an NFC reader that is requesting payment information). In some examples, the hardware button is a mechanical button or a solid state button. In some examples, the button is a switch or any other type of toggle. In some examples, the button has a fixed position relative to the electronic device, and in particular, relative to the display of the electronic device such that the electronic device may display prompts based on a position of the button. In some examples, the button is a solid-state button that operates according to capacitive and/or resistive touch, and/or is responsive to changes in the intensity of input without having a mechanical switch that is depressed to activate the button and instead monitors whether an intensity of the input is above an intensity threshold that corresponds to activation of the solid-state button. In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) receives one or more activations (e.g.,  4020 ) of the hardware button of the electronic device, and in response to receiving the one or more activations of the hardware button, the electronic device displays, on the display (e.g.,  4002 ), an authentication progress indicator (e.g.,  4022 ,  4024 ,  4030 ,  4032 ,  4034 ). In some examples, displaying the authentication progress indicator includes displaying an animation of the authentication progress indicator transitioning from a location of the prompt (e.g.,  4016 ) to a final position of the authentication progress indicator. In some examples, the authentication indicator provides a status of the authentication (e.g., in progress, successful, unsuccessful). In some examples, the animation includes displaying (e.g., maintaining the display of) the authentication progress indicator while the authentication progress indicator transitions (e.g., translates) from the location of the prompt to the final position. In some examples, the animation includes a visual effect where the authentication progress indicator appears to slide out of the prompt. In some examples, the authentication progress indicator is displayed with (or overlaid on) the user interface (e.g.,  4014 ) (or the transaction user interface region). Prompting the user to activate a hardware button guides the user to perform an action at the device in order to complete a transaction. Prompting the user in this manner enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. Displaying an authentication progress indicator provides feedback to the user regarding the status of the authentication. Improved feedback enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device), which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) concurrently displays ( 4122 ), on the display (e.g.,  4002 ), a first application (e.g., corresponding to  4006 ,  4008 ) in a first region (e.g.,  4007 ,  4009 ) and a second application (e.g., corresponding to  4006 ,  4008 ) in a second region (e.g.,  4007 ,  4009 ), the second application being adjacent to (e.g., next to, proximate to, within a predetermined distance of) the first application. In some examples, the electronic device displays ( 4124 ), on the display, a second transaction interface (e.g.,  4014 ). In some examples, the second transaction interface is the first transaction interface. In some examples, the second transaction interface is displayed overlaid on the first application and/or the second application. In some examples, in accordance ( 4126 ) with a determination that the second transaction interface corresponds to the first application, the electronic device modifies a first visual characteristic (e.g., obscure, darken, blur) of the first application. In some examples, the second transaction interface corresponds to the first application when the first application includes information about the good or service (or transaction) that is being purchased (or completed) using (or via) the second transaction interface. In some examples, this determination is made while displaying the second transaction interface. In some examples, in accordance ( 4130 ) with a determination that the second transaction interface corresponds to the second application, the electronic device (e.g.,  100 ,  300 ,  500 ,  4000 ) modifies a first visual characteristic (e.g., obscure, darken, blur) of the second application. In some examples, the second transaction interface corresponds to the first application when the first application includes information about the good or service (or transaction) that is being purchased (or completed) using (or via) the second transaction interface. In some examples, this determination is made while displaying the second transaction interface. 
     In some examples, modifying the first visual characteristic of the first application includes modifying a second visual characteristic of the second application. In some examples, modifying the second visual characteristic of the second application includes increasing darkening and/or increasing blur radius of a blur effect applied to the second application to a greater degree (or amount) than with respect to the first application. In some examples, modifying the first visual characteristic of the second application includes modifying a second visual characteristic of the first application. In some examples, modifying the second visual characteristic of the first application includes increasing darkening and/or increasing blur radius of a blur effect applied to the first application to a greater degree (or amount) than with respect to the second application. Modifying the visual characteristic of one application to a greater degree than with respect to another application provides feedback to the user as to which application is more relevant at the time. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. 
     In some examples, modifying the first visual characteristic of the first application includes displaying ( 4128 ) the first application in the second region in accordance with a determination that the second region is closer (e.g., nearer) to the first portion of the electronic device (e.g., biometric sensor) than the first region. In some examples, displaying the first application in the second region includes ceasing to display the first application in the first region. In some examples, modifying the first visual characteristic of the second application includes displaying ( 4132 ) the second application in the first region in accordance with a determination that the first region is closer (e.g., nearer) to the first portion of the electronic device (e.g., biometric sensor) than the second region. In some examples, displaying the second application in the first region includes ceasing to display the second application in the second region. In some examples, the electronic device displays an animation of the first application swapping places with the second application. 
     In some examples, in accordance with the determination that the second transaction interface (e.g.,  4014 ) corresponds to the first application, the second transaction interface includes an indication of the first application (e.g., the name of the first application). In some examples, in accordance with the determination that the second transaction interface corresponds to the second application, the second transaction interface includes an indication of the second application (e.g., the name of the second application). 
     Note that details of the processes described above with respect to method  4100  (e.g.,  FIGS. 41A-41C ) are also applicable in an analogous manner to the methods described below/above. For example, method  3700 , method  3900 , and/or method  4300  optionally include one or more of the characteristics of the various methods described above with reference to method  4100 . For example, error icon  4028 , as described in method  4100 , can be used to indicate that the biometric sensor is obstructed when biometric authentication is being performed in the processes described with respect to method  3700  and method  3900 . For brevity, these details are not repeated below. 
       FIGS. 42A-42P  illustrate exemplary user interfaces for orienting the device to enroll a biometric feature (e.g., a face for later use in biometric authentication), in accordance with some examples. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIGS. 43A-43C . 
       FIG. 42A  illustrates electronic device  4200  (e.g., portable multifunction device  100 , device  300 , device  500 ). In the exemplary examples illustrated in  FIGS. 42A-42P , electronic device  4200  is a tablet. In other examples, electronic device  4200  can be a different type of electronic device, such as a wearable device (e.g., a smartwatch). Electronic device  4200  includes display  4202 , one or more input devices (e.g., touchscreen of display  4202 , a button, and a microphone), and a wireless communication radio. In some examples, the electronic device includes a plurality of cameras. In some examples, the electronic device includes only one camera. In  FIG. 42A , the electronic device includes biometric sensor  4203 . In some examples, the biometric sensor is one or more biometric sensors that can include a camera, such as an infrared camera, a thermographic camera, or a combination thereof. In some examples, biometric sensor  4203  is biometric sensor  703 . In some examples, the one or more biometric sensors include one or more fingerprint sensors (e.g., a fingerprint sensor integrated into a button). In some examples, the device further includes a light-emitting device (e.g., light projector), such as an IR flood light, a structured light projector, or a combination thereof. The light-emitting device is, optionally, used to illuminate the biometric feature (e.g., the face) during capture of biometric data of biometric features by the one or more biometric sensors. 
     At  FIG. 42A , a user wishes to set up biometric (e.g., face) authentication on electronic device  4200 . Successfully setting up biometric authentication on the device enables a user to perform operations on the device that require authentication (e.g., unlocking the device) by presenting the user&#39;s face for biometric authentication. To set up biometric authentication on the electronic device, a user must first enroll her face. The process for enrolling the face can include some or all of the features (or processes) of  FIGS. 11A-11O . 
     As illustrated in  FIG. 42A , electronic device  4200  displays introduction user interface (UI)  4206  with initiate affordance  4208 . Electronic device  4200  receives input  4210  at initiate affordance  4208  to start the process of enrolling the user&#39;s face for biometric authentication. 
     At  FIG. 42B , in response to receiving input  4210  at initiate affordance  4208 , electronic device  4200  determines that the orientation of the device is not suitable for enrolling the user&#39;s face. In some examples, a suitable orientation for enrolling the user&#39;s face is a portrait orientation that is upright (e.g., vertical), where the portrait orientation is such that biometric sensor  4203  is at the top of the device (e.g., the side of the device that is farthest away from the ground). In response to determining that the orientation of the device is not suitable for enrolling the user&#39;s face, electronic device  4200  displays (e.g., replaces display of introduction UI  4206  with) one or more prompts to prompt the user to orient electronic device  4200  to a suitable orientation. More specifically, electronic device  4200  determines that electronic device  4200  is in a substantially horizontal orientation (e.g., approximately parallel to the ground). As a result, as depicted in  FIG. 42B , electronic device  4200  displays prompt  4212 A to prompt the user to lift electronic device  4200  to an upright position. 
     In some examples, in response to receiving input  4210  at initiate affordance  4208 , electronic device determines that the orientation of the device is suitable for enrolling the user&#39;s face. In some examples, upon determining that the orientation if suitable for enrolling the user&#39;s face, electronic device  4200  automatically initiates a process for enrolling the user&#39;s face, as described below with respect to  FIG. 42D . 
     At  FIG. 42C , in response to determining that electronic device  4200  is in an upright position but not in a portrait orientation (e.g., the user has lifted the device off the table in response to prompt  4212 A), electronic device  4200  displays (e.g., replaces display of prompt  4212 A with) prompt  4212 B to prompt the user to rotate electronic device  4200  to a portrait orientation (e.g., with the biometric sensor  4203  at the top). Specifically, prompt  4212 B prompts the user to rotate in a specific direction such that minimal rotation is required to achieve the desired (or suitable) orientation. For example, rotating electronic device  4200  clockwise requires less rotation to achieve the desired orientation rather than rotating the device counterclockwise. 
     At  FIG. 42D , in response to determining that electronic device  4200  is in a suitable orientation, electronic device  4200  automatically initiates a process for enrolling the user&#39;s face. As illustrated in  FIGS. 42D-42F , after initiating the process for enrolling the user&#39;s face, electronic device  4200  displays face enrollment UI  4214 . Face enrollment UI  4214  includes some or all of the features of face enrollment UI  1104 . 
     At  FIG. 42G , after successfully completing the enrollment of the user&#39;s face, electronic device  4200  displays (e.g., replaces display of face enrollment UI  4214  with) scan completion interface  4216 , which includes continue affordance  4218 . Scan completion interface  4216  includes some or all of the features of scan completion interface  1130 . 
     After completing enrollment of the user&#39;s face, a second iteration of the enrollment process is performed without requiring that the user re-orient the device. As depicted in  FIG. 42G , while displaying scan completion interface  4216 , electronic device  4200  receives input  4220  at continue affordance  4218  to initiate the second iteration of the enrollment process. 
     At  FIG. 42H , in response to receiving input  4220  at continue affordance  4218 , electronic device  4200  initiates a second iteration of the enrollment process, analogous to the processes described above with respect to  FIGS. 42D-42F . Electronic device  4200  initiates the second iteration without prompting the user to re-orient the device to an orientation different from its current orientation. Initiating the second iteration of the enrollment process includes displaying second face enrollment UI  4222 . Second face enrollment UI  4222  includes some or all of the features of second face enrollment UI  1138 . 
     At  FIG. 42I , after successfully completing the second iteration of the enrollment process, electronic device  4200  displays (e.g., replaces display of second face enrollment UI  4222  with) second scan completion interface  4224 , which includes continue affordance  4226 . Second scan completion interface  4224  includes some or all of the features of second scan completion interface  1156 . As illustrated in  FIG. 42I , electronic device  4200  receives input  4228  at continue affordance  4226 . 
     At  FIG. 42J , in response to receiving input  4228  at continue affordance  4226 , electronic device  4200  displays (e.g., replaces display of second scan completion interface  4224  with) enrollment completion interface  4230 , providing an indication to the user that biometric authentication has been successfully set up on electronic device  4200 . Enrollment completion interface  4230  includes some or all of the features of enrollment completion interface  1166 . 
     At  FIG. 42K , after biometric authentication has been set up on electronic device  4200 , a user can unlock electronic device  4200  (e.g., transition the device from a locked state to an unlocked state) using biometric authentication by presenting the user&#39;s face to biometric sensor  4203 . In some examples, the user initiates biometric authentication to unlock the device by lifting (or raising) electronic device  4200  (e.g., from a substantially horizontal orientation). While electronic device  4200  is being lifted, electronic device  4200  detects a change in orientation of the device, and in response, initiates biometric authentication to unlock the device. It is noted that while electronic device  4200  is in a locked state, electronic device  4200  displays locked state interface  4232  including biometric sensor indicator  4234 , which provides an indication to the user of the location of biometric sensor  4203 , and lock icon  4236 , which provides an indication that electronic device  4200  is in a locked state. In some examples, electronic device  4200  does not display biometric sensor indicator  4234  while electronic device  4200  is in a locked state. 
     As depicted in  FIG. 42L , when electronic device  4200  initiates biometric authentication, the user is holding electronic device  4200  such that the user&#39;s face is outside field of view  4238  of biometric sensor  4203 . In some examples, the user&#39;s face is outside field of view  4238  when more than a threshold portion of the face is outside the field of view. In some examples, the user&#39;s face is outside field of view  4238  when no face is detected within the field of view. While attempting to biometrically authenticate the user&#39;s face, electronic device  4200  is unable to obtain sufficient information about the user&#39;s face using biometric sensor  4203 . As a result, electronic device  4200  does not have sufficient information for comparison with the stored authorized credentials, which were generated from the enrollment process described above with respect to  FIGS. 42D-42J . 
     At  FIG. 42M , upon determining that the user&#39;s face is outside field of view  4238 , electronic device  4200  displays error indication  4240 , which provides an indication to the user that the user&#39;s face is outside field of view  4238 . (Error indication  4240  includes some or all of the features of error indication  3814 G.) Additionally, upon determining that the user&#39;s face is outside field of view  4238 , electronic device  4200  does not automatically retry authentication. In some examples, electronic device  4200  also displays biometric sensor indicator  4234 . In some examples, if sufficient information had been obtained but authentication nevertheless failed (e.g., the obtained information did not match the stored authorized credentials), electronic device  4200  automatically retries biometric authentication. 
     As depicted in  FIG. 42N , after learning from error indication  4240  that the user&#39;s face is outside field of view  4238  of biometric sensor  4203 , the user moves her face into field of view  4238  such that the user&#39;s face is within field of view  4238 . In response to detecting that the cause of error indication  4240  has been corrected (e.g., detects more than a threshold amount of the user&#39;s face), electronic device  4200  automatically retries biometric authentication. Upon determining that authentication is successful as a result of retrying biometric authentication (e.g., the information obtained using biometric sensor  4203  matches the stored authorized credentials), electronic device  4200  transitions from a locked state to an unlocked state. After transitioning to the unlocked state, electronic displays unlocked state interface  4242 . 
     In some examples, while displaying unlocked state interface  4242 , electronic device  4200  receives a request (e.g., an upward swipe starting from within a region adjacent to the bottom edge of display  4202 ) to access restricted content on the device (e.g., home screen  4244  of  FIG. 42O , the most recently used application). In response to receiving the request to access restricted content, electronic device  4200  displays home screen  4244 , including a plurality of icons that, when activated, result in launching an application corresponding to the activated icon. In some examples, instead of displaying home screen  4244 , electronic device  4200  displays the most recently used application (e.g., a user interface of the application). It is noted that the above processes described above with respect to  FIGS. 42K-42O  are performed when electronic device  4200  is in a landscape orientation. However, in some examples, some or all of the processes described above with respect to  FIGS. 42K-42N  can be performed when electronic device  4200  is in a portrait orientation. 
     In some examples, instead of transitioning to an unlocked state as described with respect to  FIG. 42N , electronic device  4200  maintains a locked state if the obtained information does not match the stored authorized credentials. In some examples, as depicted in  FIG. 42P , upon determining that the obtained information does not match the stored authorized credentials, electronic device  4200  displays locked state interface  4232  while alternating the position of lock icon  4236  such that it simulates a “shake” effect, thereby providing an indication to the user that electronic device  4200  remains in a locked state. 
       FIGS. 43A-43C  are flow diagrams illustrating a method for orienting the device to enroll a biometric feature (e.g., a face for later use in biometric authentication), in accordance with some examples. Method  4300  is performed at an electronic device (e.g.,  100 ,  300 ,  500 ,  4200 ) with a display (e.g.,  4202 ) and one or more biometric sensor (e.g.,  4203 ) (e.g., a first biometric sensor of a device with a plurality of biometric sensors) (e.g., a fingerprint sensor, a contactless biometric sensor (e.g., a biometric sensor that does not require physical contact, such as a thermal or optical facial recognition sensor), an iris scanner). In some examples, the one or more biometric sensors include one or more cameras. Some operations in method  4300  are, optionally, combined, the orders of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  4300  provides an intuitive way for prompting a user to orient a device to enroll a biometric feature. The method reduces the cognitive burden on a user for enrolling a biometric feature (e.g., a face for later use in biometric authentication), thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to enroll a biometric feature faster and more efficiently conserves power and increases the time between battery charges. 
     The electronic device (e.g.,  100 ,  300 ,  500 ,  4200 ) displays ( 4302 ), on the display (e.g.,  4202 ), a biometric enrollment user interface (e.g.,  4206 ) for initiating biometric enrollment with the one or more biometric sensors. 
     While displaying ( 4304 ) the biometric enrollment user interface, the electronic device receives input (e.g.,  4210 ) (e.g., touch gesture (e.g., tap), spoken user input) corresponding to a request to initiate biometric enrollment. 
     In response ( 4306 ) to receiving the input (e.g.,  4210 ) and in accordance ( 4308 ) with a determination that an orientation of the electronic device (e.g., current orientation, an orientation of the electronic device at (or near) the time of the input) satisfies a set of enrollment criteria, the electronic device initiates a process for enrolling a biometric feature with the one or more biometric sensors (e.g.,  4203 ). In some examples, the set of enrollment criteria includes whether the electronic device is oriented in a portrait orientation with respect to a frame of reference (e.g., Earth, ground), whether the one or more biometric sensors are oriented (or located) at a particular side of the electronic device in the portrait orientation (e.g., the side furthest away from Earth), or whether the electronic device is oriented such that it is not approximately parallel with respect to the ground. In some examples, the set of enrollment criteria includes whether the electronic device is in a certain (e.g., proper) orientation relative to a biometric feature (e.g., face) (e.g., a primary plane of the device (e.g., a plane defined by the display of the device) is facing the biometric feature). In some examples, initiating a process for enrolling a biometric feature includes capturing data corresponding to a face of a user using the one or more biometric sensors. 
     In response ( 4306 ) to receiving the input (e.g.,  4210 ) and in accordance ( 4322 ) with a determination that the orientation of the electronic device does not satisfy the set of enrollment criteria, outputting one or more prompts (e.g.,  4212 A-B) (e.g., a visual, audio and/or tactile prompt) to change the orientation of the electronic device to a different orientation that satisfies the set of enrollment criteria. Outputting one or more prompts when the set of enrollment criteria are not satisfied provides the user with feedback as to what corrective actions to take to continue enrolling a biometric feature. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. 
     In some examples, outputting the one or more prompts includes outputting ( 4324 ) a first prompt (e.g.,  4212 A) to orient the electronic device to an initial orientation. In some examples, the initial orientation is an orientation such that the electronic device is not approximately parallel with respect to the ground. In some examples, the initial orientation is an orientation such that the electronic device is approximately parallel to the force of gravity. In some examples, the set of enrollment criteria includes a requirement that a primary plane of a device be substantially aligned with a predetermined plane (e.g., a plane that is substantially normal to the ground) such that the display of the device is substantially vertical. In some examples, the set of enrollment criteria includes a requirement that the primary plane of the device is not substantially aligned with a (second) predetermined plane (e.g., a plane that is substantially parallel to the ground) such that the device is not resting on a horizontal surface while attempting to enroll a biometric feature. In some examples, outputting the one or more prompts includes, subsequent to outputting the first prompt (e.g.,  4212 A), outputting ( 4326 ) a second prompt (e.g.,  4212 B) to orient the electronic device to the different orientation that satisfies the set of enrollment criteria, the first prompt being different from the second prompt. In some examples, the electronic device outputs the first prompt without outputting the second prompt. In some examples, the electronic device ceases outputting the first prompt when the orientation of the electronic device changes to the initial orientation. In some examples, the electronic device outputs the second prompt when the orientation of the electronic device changes to the initial orientation. In some examples, the electronic device outputs the second prompt without outputting the first prompt (e.g., when the electronic device is already in the initial orientation). In some examples, the set of enrollment criteria includes whether the electronic device is oriented in a portrait orientation with respect to a frame of reference (e.g., Earth, ground), whether the one or more biometric sensors are oriented (or located) at a particular side of the electronic device in the portrait orientation (e.g., the side furthest away from Earth), or whether the electronic device is oriented such that it is not approximately parallel with respect to the ground. Outputting the first prompt without outputting the second prompt provides improved feedback to the user as it reduces the chances of confusion when the user is taking corrective actions to trigger enrollment of a biometric feature. Providing improved visual feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. In some examples, no indicator is displayed during biometric authentication. 
     In some examples, outputting the one or more prompts includes outputting a third prompt (e.g.,  4212 B) to rotate the electronic device (e.g., about an axis perpendicular to the electronic device) to the different orientation that satisfies the set of enrollment criteria, the third prompt being based on the orientation of the electronic device while receiving the input. In some examples, the third prompt is the second prompt. In some examples, in accordance with a determination that the orientation of the electronic device is in a first orientation, the electronic device outputs a first rotation prompt to rotate the electronic device to the different orientation that satisfies the set of enrollment criteria. In some examples, in accordance with a determination that the orientation of the electronic device is in a second orientation that is different from the first orientation, the electronic device outputs a second rotation prompt to rotate the electronic device to the different orientation that satisfies the set of enrollment criteria, the second rotation prompt being different from the first rotation prompt. In some examples, the first rotation prompt or the second rotation prompt is the second prompt. In some examples, the set of enrollment criteria includes whether the electronic device is oriented in a portrait orientation with respect to a frame of reference (e.g., Earth, ground), whether the one or more biometric sensors are oriented (or located) at a particular side of the electronic device in the portrait orientation (e.g., the side furthest away from Earth), or whether the electronic device is oriented such that it is not approximately parallel with respect to the ground. Outputting a prompt based on the orientation of the device provides feedback to the user as to an efficient process for achieving a suitable orientation of the device for enrolling a biometric feature. Providing improved feedback to the user enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples outputting the one or more prompts includes outputting a fourth prompt (e.g.,  4212 B) to rotate (e.g., a long an axis parallel to a primary plane (e.g., a plane defined by the display of the device) of the device) the electronic device (e.g., about an axis perpendicular to the electronic device) to the different orientation that satisfies the set of enrollment criteria, the third prompt being based on an alignment of a primary plane of the device (e.g., a plane defined by the display of the device) to a predetermined plane (e.g., a plane that is substantially normal to the ground; a plane that is substantially parallel to the ground). In some examples, the electronic device outputs the fourth prompt in accordance with a determination that the electronic device is oriented substantially parallel to the ground. In some examples, the set of enrollment criteria includes a requirement that a primary plane of a device be substantially aligned with a predetermined plane (e.g., a plane that is substantially normal to the ground) such that the display of the device is substantially vertical. In some examples, the set of enrollment criteria includes a requirement that the primary plane of the device is not substantially aligned with a (second) predetermined plane (e.g., a plane that is substantially parallel to the ground) such that the device is not resting on a horizontal surface while attempting to enroll a biometric feature. 
     In some examples, subsequent to initiating the process for enrolling the biometric feature (e.g., subsequent to successfully enrolling a biometric feature), the electronic device (e.g.,  100 ,  300 ,  500 ,  4200 ) receives a request to perform an operation that requires authentication (e.g., a request to unlock the device (e.g., perform a swipe at a predefined location)). In some examples, the electronic device receives the request to perform the operation that requires authentication subsequent to performing (or completing) biometric enrollment. In some examples, the electronic device receives the request to perform the operation that requires authentication subsequent to outputting the one or more prompts (e.g.,  4212 A-B) (e.g., a visual, audio and/or tactile prompt) to change the orientation of the electronic device to the different orientation that satisfies the set of enrollment criteria. In some examples, in response to receiving the request to perform the operation that requires authentication, the electronic device attempts authentication using the one or more biometric sensors (e.g.,  4203 ) (e.g., that includes obtaining data by the one or more biometric sensors). In some examples, after attempting (e.g., unsuccessfully attempting) authentication using the one or more biometric sensors and in accordance with a determination that data obtained by the one or more biometric sensors corresponds to less than a threshold amount of a biometric feature (e.g., part of a face/fingerprint, not a whole face/fingerprint) (e.g., due to the face being outside the field of view (e.g.,  4238 ), the electronic device forgoes retrying authentication. In some examples, the electronic device forgoes automatically retrying authentication. In some examples, after attempting authentication using the one or more biometric sensors, the electronic device forgoes retrying authentication due to biometric authentication having failed more than a predetermined number of times (e.g., 5, 10, 15) since the last successful authentication with the device. In some examples, the electronic device forgoes retrying authentication without an explicit request to perform an operation that requires authentication (e.g., a request to unlock the device (e.g., perform a swipe at a predefined location)). In some examples, after an initial attempt at authentication does not succeed, the electronic device retries biometric authentication if a determination is not made that data obtained by the one or more biometric sensors corresponds to only a portion of a biometric feature. Forgoing retrying authentication when less than a threshold amount of a biometric feature is obtained avoids the user consuming the permitted number of attempts on repeated requests (e.g., repeated requests of the same type), thereby conserving at least one attempt for requests for other operations that require biometric authentication. Conserving at least one attempt enhances the operability of the device and makes the user-device interface more efficient (e.g., by avoiding exhaustion of authentication attempts on repeated, similar requests) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, after attempting (e.g., unsuccessfully attempting) authentication using the one or more biometric sensors and in accordance with a determination that the data obtained by the one or more biometric sensors corresponds to not less (e.g., more) than the threshold amount of the biometric feature, the electronic device retries authentication. Automatically retrying authentication when a threshold amount of the biometric feature is obtained provides the user the ability to attempt authentication when the conditions are appropriate without requiring the user to explicitly request retrying authentication. Performing an operation when a set of conditions has been met without requiring further user input enhances the operability of the device (e.g., increases the chances of successful authentication) and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In some examples, in accordance with a determination that authentication resulting from retrying authentication is successful, the electronic device (e.g.,  100 ,  300 ,  500 ,  4200 ) performs an operation corresponding to the request. In some examples, in accordance with a determination that authentication resulting from retrying authentication is not successful, the electronic device forgoes performing the operation corresponding to the request. In some examples, authentication is successful when the biometric information captured using the one or more biometric sensors corresponds to (or matches) authorized credentials (e.g., stored information about a biometric feature (e.g., face, fingerprint) that are authorized for use in biometric authentication). In some examples, authentication is unsuccessful when the biometric information captured using the one or more biometric sensors does not correspond to (or match) authorized credentials (e.g., stored information about a biometric feature (e.g., face, fingerprint) that are authorized for use in biometric authentication). Forgoing performing the operation when authentication is not successful enhances device security by preventing fraudulent and/or unauthorized access to the device. Improving security measures of the device enhances the operability of the device by preventing unauthorized access to content and operations and, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more efficiently. 
     In some examples, subsequent to outputting the one or more prompts (e.g.,  4212 A-B) (e.g., a visual, audio and/or tactile prompt) to change the orientation of the electronic device to the different orientation that satisfies the set of enrollment criteria, the electronic device (e.g.,  100 ,  300 ,  500 ,  4200 ) detects ( 4328 ) that the current orientation of the electronic device satisfies the set of enrollment criteria. In some examples, in response ( 4330 ) to determining that the current orientation of the electronic device satisfies the set of enrollment criteria, the electronic device initiates the process for enrolling the biometric feature with the one or more biometric sensors. In some examples, the set of enrollment criteria includes whether the electronic device is oriented in a portrait orientation with respect to a frame of reference (e.g., Earth, ground), whether the one or more biometric sensors are oriented (or located) at a particular side of the electronic device in the portrait orientation (e.g., the side furthest away from Earth), or whether the electronic device is oriented such that it is not approximately parallel with respect to the ground. In some examples, the set of enrollment criteria includes a requirement that a primary plane of a device be substantially aligned with a predetermined plane (e.g., a plane that is substantially normal to the ground) such that the display of the device is substantially vertical. In some examples, the set of enrollment criteria includes a requirement that the primary plane of the device is not substantially aligned with a (second) predetermined plane (e.g., a plane that is substantially parallel to the ground) such that the device is not resting on a horizontal surface while attempting to enroll a biometric feature. In some examples, the set of enrollment criteria includes whether the electronic device is in a certain (e.g., proper) orientation relative to a biometric feature (e.g., face) (e.g., a primary plane of the device (e.g., a plane defined by the display of the device) is facing the biometric feature). 
     In some examples, initiating the process for enrolling the biometric feature with the one or more biometric sensors includes successfully enrolling the biometric feature. In some examples, subsequent to successfully enrolling the biometric feature, the electronic device (e.g.,  100 ,  300 ,  500 ,  4200 ) outputs ( 4312 ) a prompt (e.g., corresponding to  4222 ) to enroll the biometric feature for a second time with the one or more biometric sensors. In some examples, the electronic device outputs the prompt to enroll the biometric feature without prompting to change the orientation of the electronic device. 
     In some examples, initiating the process for enrolling the biometric feature with the one or more biometric sensors includes ( 4310 ) successfully enrolling the biometric feature. In some examples, subsequent to successfully enrolling the biometric feature, the electronic device (e.g.,  100 ,  300 ,  500 ,  4200 ) receives ( 4314 ) a request to perform an operation that requires authentication (e.g., a request to unlock the device (e.g., perform a swipe at a predefined location), request to access home screen (e.g.,  4244 )). In some examples, in response ( 4316 ) to receiving the request to perform the operation that requires authentication and in accordance ( 4318 ) with a determination that data obtained by the one or more biometric sensors corresponds to (e.g., matches) the enrolled biometric feature, the electronic device performs the operation that requires authentication. In some examples, in response to receiving the request to perform the operation that requires authentication, the electronic device performs authentication (or attempts to authenticate) using the one or more biometric sensor (e.g.,  4203 ). In some examples, in response ( 4316 ) to receiving the request to perform the operation that requires authentication and in accordance ( 4320 ) with a determination that data obtained by the one or more biometric sensors does not correspond to (e.g., does not match) the enrolled biometric feature, the electronic device forgoes performing the operation that requires authentication. 
     Note that details of the processes described above with respect to method  4300  (e.g.,  FIGS. 43A-43C ) are also applicable in an analogous manner to the methods described below/above. For example, method  3700 , method  3900 , and/or method  4100  optionally include one or more of the characteristics of the various methods described above with reference to method  4300 . For example, the processes described in method  4300  for enrolling a biometric feature can be used to enroll a face for later use in biometric authentication, such as retrying biometric authentication at a passcode entry user interface, as described in method  3700 . As another example, the enrolled face can be used to authorized payment for goods, as described in method  4100 . For brevity, these details are not repeated below. 
     The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the techniques and their practical applications. Others skilled in the art are thereby enabled to best utilize the techniques and various embodiments with various modifications as are suited to the particular use contemplated. 
     Although the disclosure and examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the disclosure and examples as defined by the claims. 
     As described above, one aspect of the present technology is the gathering and use of data available from various sources to improve the delivery to users of invitational content or any other content that can be of interest to them. The present disclosure contemplates that in some instances, this gathered data can include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, home addresses, or any other identifying information. 
     The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver targeted content that is of greater interest to the user. Accordingly, use of such personal information data enables calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. 
     The present disclosure further contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. For example, personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection should occur only after receiving the informed consent of the users. Additionally, such entities would take any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services. In another example, users can select not to provide location information for targeted content delivery services. In yet another example, users can select to not provide precise location information, but permit the transfer of location zone information. 
     Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publically available information.