recursal/MDN huggingface dataset:
PerformanceTiming: loadEventStart property
==========================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface's `PerformanceNavigationTiming.loadEventStart` read-only property instead.


 The legacy
 **`PerformanceTiming.loadEventStart`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, when the `load` event was sent for the
 current document. If this event has not yet been sent, it returns `0.`

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: toJSON() method
==================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


The legacy **`toJSON()`** method of the `PerformanceTiming` interface is a serializer; it returns a JSON representation of the `PerformanceTiming` object.

Syntax
------


```js
toJSON()
```

### Parameters

None.

### Return value

A `JSON` object that is the serialization of the `PerformanceTiming` object.

Specifications
--------------

| Specification |
| --- |
| Navigation Timing Level 2 # dom-performancetiming-tojson |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* `JSON`
PerformanceTiming: redirectStart property
=========================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.redirectStart`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, the first HTTP redirect starts. If there is no
 redirect, or if one of the redirect is not of the same origin, the value returned is
 `0`.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: responseEnd property
=======================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.responseEnd`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, when the browser received the last byte of the
 response, or when the connection is closed if this happened first, from the server from
 a cache or from a local resource.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: unloadEventStart property
============================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.unloadEventStart`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, the `unload` event has been thrown. If
 there is no previous document, or if the previous document, or one of the needed
 redirects, is not of the same origin, the value returned is `0`.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: domComplete property
=======================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.domComplete`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, when the parser finished its work on the main
 document, that is when its `Document.readyState` changes to
 `'complete'` and the corresponding `readystatechange` event is
 thrown.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: redirectEnd property
=======================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.redirectEnd`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, the last HTTP redirect is completed, that is when
 the last byte of the HTTP response has been received. If there is no redirect, or if one
 of the redirect is not of the same origin, the value returned is `0`.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `Performance` interface it belongs to.
PerformanceTiming: domContentLoadedEventStart property
======================================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.domContentLoadedEventStart`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, right before the parser sent the
 `DOMContentLoaded` event, that is right after all the scripts that need to be
 executed right after parsing has been executed.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: requestStart property
========================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.requestStart`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, when the browser sent the request to obtain the
 actual document, from the server or from a cache. If the transport layer fails after the
 start of the request and the connection is reopened, this property will be set to the
 time corresponding to the new request.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: connectStart property
========================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.connectStart`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, where the request to open a connection is sent to
 the network. If the transport layer reports an error and the connection establishment is
 started again, the last connection establishment start time is given. If a persistent
 connection is used, the value will be the same as
 `PerformanceTiming.fetchStart`.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: domContentLoadedEventEnd property
====================================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.domContentLoadedEventEnd`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, right after all the scripts that need to be
 executed as soon as possible, in order or not, has been executed.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: secureConnectionStart property
=================================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming` interface instead.

 The legacy
 **`PerformanceTiming.secureConnectionStart`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, where the secure connection handshake starts. If
 no such connection is requested, it returns `0`.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: msFirstPaint property
========================================

**Non-standard:** This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

**`msFirstPaint`** is a read-only property which gets the time
 when the document loaded by the window object began to be displayed to the user.

 Put another way, `msFirstPaint` utilizes the browser to measure when the
 first content completes being painted in the window. It is available from JavaScript and
 can be reported from the field.

This proprietary property is specific to Internet Explorer and Microsoft Edge.

Syntax
------


```js
p = object.msFirstPaint
```

Value
-----

 An Integer value that represents the time when the document began to be displayed or 0
 if the document could not be loaded.

 The numerical value reported represents the number of milliseconds between the recorded
 time and midnight January 1, 1970 (UTC).

This property is supported only for documents displayed in IE9 Standards mode.

Example
-------

 The following example shows how to calculate the time that is required to request the
 document before the document begins to display for the user.


```js
const oTiming = window.performance.timing;
const iTimeMS = oTiming.msFirstPaint - oTiming.navigationStart;
```
PerformanceTiming: unloadEventEnd property
==========================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.unloadEventEnd`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, the `unload` event handler finishes. If
 there is no previous document, or if the previous document, or one of the needed
 redirects, is not of the same origin, the value returned is `0`.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.
PerformanceTiming: connectEnd property
======================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

**Warning:** This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the `PerformanceNavigationTiming`
 interface instead.


 The legacy
 **`PerformanceTiming.connectEnd`**
 read-only property returns an `unsigned long long` representing the moment,
 in milliseconds since the UNIX epoch, where the connection is opened network. If the
 transport layer reports an error and the connection establishment is started again, the
 last connection establishment end time is given. If a persistent connection is used, the
 value will be the same as `PerformanceTiming.fetchStart`. A connection is
 considered as opened when all secure connection handshake, or SOCKS authentication, is
 terminated.

Value
-----

An `unsigned long long`.

Specifications
--------------

 This feature is no longer on track to become a standard, as the Navigation Timing specification has marked it as deprecated.
 Use the `PerformanceNavigationTiming` interface instead.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* The `PerformanceTiming` interface it belongs to.