DocumentationsearchSearchrocket_launchGet startedInstallationaddFundamentalsaddFirst stepsaddcodeDevelopConceptsaddAPI referenceremovePAGE ELEMENTSWrite and magicaddText elementsaddData elementsaddChart elementsaddInput widgetsremoveBUTTONSst.buttonst.download_buttonst.form_submit_buttonlinkst.link_buttonst.page_linkSELECTIONSst.checkboxst.color_pickerst.multiselectst.radiost.selectboxst.select_sliderst.toggleNUMERICst.number_inputst.sliderDATE & TIMEst.date_inputst.time_inputTEXTst.chat_inputlinkst.text_areast.text_inputMEDIA & FILESst.camera_inputst.data_editorlinkst.file_uploaderMedia elementsaddLayouts and containersaddChat elementsaddStatus elementsaddThird-party componentsopen_in_newAPPLICATION LOGICNavigation and pagesaddExecution flowaddCaching and stateaddConnections and secretsaddCustom componentsaddUtilitiesaddConfigurationaddTOOLSApp testingaddCommand lineaddTutorialsaddQuick referenceaddweb_assetDeployConceptsaddStreamlit Community CloudaddStreamlit in Snowflakeopen_in_newOther platformsaddschoolKnowledge baseFAQInstalling dependenciesDeployment issuesHome/Develop/API reference/Input widgets/st.download_buttonst.download_buttonStreamlit VersionVersion 1.34.0Version 1.33.0Version 1.32.0Version 1.31.0Version 1.30.0Version 1.29.0Version 1.28.0Version 1.27.0Version 1.26.0Version 1.25.0Version 1.24.0Version 1.23.0Version 1.22.0Version 1.21.0Version 1.20.0Version 1.19.0Version 1.18.0Version 1.17.0Version 1.16.0Version 1.15.0Version 1.14.0Version 1.13.0Streamlit in SnowflakeDisplay a download button widget.
This is useful when you would like to provide a way for your users
to download a file directly from your app.
Note that the data to be downloaded is stored in-memory while the
user is connected, so it's a good idea to keep file sizes under a
couple hundred megabytes to conserve memory.
Function signature[source] st.download_button(label, data, file_name=None, mime=None, key=None, help=None, on_click=None, args=None, kwargs=None, *, type="secondary", disabled=False, use_container_width=False) Parameters

label
(str)

 
A short label explaining to the user what this button is for.
The label can optionally contain Markdown and supports the following
elements: Bold, Italics, Strikethroughs, Inline Code, and Emojis.
This also supports:

Emoji shortcodes, such as :+1:  and :sunglasses:.
For a list of all supported codes,
see https://share.streamlit.io/streamlit/emoji-shortcodes.
LaTeX expressions, by wrapping them in "$" or "$$" (the "$$"
must be on their own lines). Supported LaTeX functions are listed
at https://katex.org/docs/supported.html.
Colored text and background colors for text, using the syntax
:color[text to be colored] and :color-background[text to be colored],
respectively. color must be replaced with any of the following
supported colors: blue, green, orange, red, violet, gray/grey, rainbow.
For example, you can use :orange[your text here] or
:blue-background[your text here].

Unsupported elements are unwrapped so only their children (text contents)
render. Display unsupported elements as literal characters by
backslash-escaping them. E.g. 1\. Not an ordered list.


data
(str or bytes or file)

 
The contents of the file to be downloaded. See example below for
caching techniques to avoid recomputing this data unnecessarily.


file_name
(str)

 
An optional string to use as the name of the file to be downloaded,
such as 'my_file.csv'. If not specified, the name will be
automatically generated.


mime
(str or None)

 
The MIME type of the data. If None, defaults to "text/plain"
(if data is of type str or is a textual file) or
"application/octet-stream" (if data is of type bytes or is a
binary file).


key
(str or int)

 
An optional string or integer to use as the unique key for the widget.
If this is omitted, a key will be generated for the widget
based on its content. Multiple widgets of the same type may
not share the same key.


help
(str)

 
An optional tooltip that gets displayed when the button is
hovered over.


on_click
(callable)

 
An optional callback invoked when this button is clicked.


args
(tuple)

 
An optional tuple of args to pass to the callback.


kwargs
(dict)

 
An optional dict of kwargs to pass to the callback.


type
("secondary" or "primary")

 
An optional string that specifies the button type. Can be "primary" for a
button with additional emphasis or "secondary" for a normal button. Defaults
to "secondary".


disabled
(bool)

 
An optional boolean, which disables the download button if set to
True. The default is False.


use_container_width
(bool)

 
An optional boolean, which makes the button stretch its width to match the
parent container.
Returns(bool)  True if the button was clicked on the last run of the app,
False otherwise.
Examples
Download a large DataFrame as a CSV:

import streamlit as st

@st.cache_data
def convert_df(df):
    # IMPORTANT: Cache the conversion to prevent computation on every rerun
    return df.to_csv().encode("utf-8")

csv = convert_df(my_large_df)

st.download_button(
    label="Download data as CSV",
    data=csv,
    file_name="large_df.csv",
    mime="text/csv",
)

Download a string as a file:

import streamlit as st

text_contents = '''This is some text'''
st.download_button("Download some text", text_contents)

Download a binary file:

import streamlit as st

binary_contents = b"example content"
# Defaults to "application/octet-stream"
st.download_button("Download binary file", binary_contents)

Download an image:

import streamlit as st

with open("flower.png", "rb") as file:
    btn = st.download_button(
            label="Download image",
            data=file,
            file_name="flower.png",
            mime="image/png"
          )

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