Performance

The Performance interface represents timing-related performance information for the given page.

An object of this type can be obtained by calling the Window.performance read-only attribute.

Note: This interface and its members are available in Web Workers, except where indicated below. Note that some available parts of the interface are not yet documented (see the Performance Timeline and User Timing specs for more details.) Also note that performance markers and measures are per context. If you create a mark on the main thread (or other worker), you cannot see it in a worker thread, and vice versa.

Properties

The Performance interface doesn't inherit any properties.

Performance.navigation Read only Not available to workers: Is a PerformanceNavigation object representing the type of navigation that occurs in the given browsing context, like the amount of redirections needed to fetch the resource.
Performance.timing Read only Not available to workers: Is a PerformanceTiming object containing latency-related performance information.
Events
Performance.onresourcetimingbufferfull: Is an EventTarget which is a callback that will be called when the resourcetimingbufferfull event is fired.

Methods

The Performance interface doesn't inherit any method.

Performance.clearMarks(): Removes the given mark from the browser's performance entry buffer.
Performance.clearMeasures(): Removes the given measure from the browser's performance entry buffer.
Performance.clearResourceTimings(): Removes all performance entries with a entryType of "resource" from the browser's performance data buffer.
Performance.getEntries(): Returns a list of PerformanceEntry objects based on the given filter.
Performance.getEntriesByName(): Returns a list of PerformanceEntry objects based on the given name and entry type.
Performance.getEntriesByType(): Returns a list of PerformanceEntry objects of the given entry type.
Performance.mark(): Creates a timestamp in the browser's performance entry buffer with the given name.
Performance.measure(): Creates a named timestamp in the browser's performance entry buffer between two specified marks (known as the start mark and end mark, respectively).
Performance.now(): Returns a DOMHighResTimeStamp representing the amount of milliseconds elapsed since a reference instant.
Performance.setResourceTimingBufferSize(): Sets the browser's resource timing buffer size to the specified number of "resource" type performance entry objects.
Performance.toJSON() Not available to workers: Is a jsonizer returning a json object representing the Performance object.

Specifications

Specification	Status	Comment
High Resolution Time Level 2 The definition of 'toJSON()' in that specification.	Candidate Recommendation	Defines `toJson()` method.
High Resolution Time The definition of 'Performance' in that specification.	Recommendation	Defines `now()` method.
Navigation Timing The definition of 'Performance' in that specification.	Recommendation	Defines `timing` and `navigation` properties.
Performance Timeline Time Level 2 The definition of 'Performance extensions' in that specification.	Editor's Draft	Changes `getEntries()` interface.
Performance Timeline The definition of 'Performance extensions' in that specification.	Recommendation	Defines `getEntries()`, `getEntriesByType()` and `getEntriesByName()` methods.
Resource Timing Level 1 The definition of 'Performance extensions' in that specification.	Candidate Recommendation	Defines `clearResourceTimings()` and `setResourceTimingBufferSize()` methods and the `onresourcetimingbufferfull` property.
User Timing The definition of 'Performance extensions' in that specification.	Editor's Draft	Clarifies `mark()`, `clearMark()`, `measure()` and `clearMeasure()` methods.
User Timing The definition of 'Performance extensions' in that specification.	Recommendation	Defines `mark()`, `clearMark()`, `measure()` and `clearMeasure()` methods.

Feature	Chrome	Edge	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support (`timing` attribute)	6.0 [1]	(Yes)	7.0 (7.0)	9.0	15.0	8
`navigation` attribute	9	?	7 (7)	9.0	15	8
`now()` on regular context	20.0 -webkit 24.0	?	15.0 (15.0)	10.0	(Yes)	8
`now()` in Web workers.	33.0	?	34.0 (34.0)	?	(Yes)	No support
`toJSON()`	No support	?	25.0 (25.0)	9.0	No support	No support
`getEntries()`, `getEntriesByType()`, `getEntriesByName()`	(Yes)	?	(Yes)	(Yes)	(Yes)	11
`clearResourceTimings()`, `setResourceTimingBufferSize()`	(Yes)	?	(Yes)	(Yes)	(Yes)	No support
`onresourcetimingbufferfull`	(Yes)	?	(Yes)	No support	(Yes)	No support
`mark()`, `clearMarks()`, `measure()`, `clearMeasure()`	43.0	?	41	10	33	No support

Feature	Android	Android Webview	Edge	Firefox Mobile (Gecko)	Firefox OS	IE Phone	Opera Mobile	Safari Mobile	Chrome for Android
Basic support	(Yes)	(Yes)	(Yes)	7.0 (7.0)	1.0 (7.0)	9.0	15.0	9	(Yes)
`navigation` attribute	No support	(Yes)	?	No support	No support	9.0	(Yes)	9	(Yes)
`now()` on regular context		25.0	?	15.0 (15.0)	1.0 (15.0)	10.0	(Yes)	9	20.0 webkit 25.0
`now()` in Web workers.	No support	(Yes)	?	34.0 (34.0)	?	?	?	?	(Yes)
`toJSON()`	No support	No support	?	25.0 (25.0)	1.2 (25.0)	10.0	No support	?	No support
`getEntries()`, `getEntriesByType()`, `getEntriesByName()`	4.4	(Yes)	?	25.0 (25.0)	1.2 (25.0)	10.0	33	11	59
`clearResourceTimings()`, `setResourceTimingBufferSize()`	No support	(Yes)	?	(Yes)	(Yes)	(Yes)	33	No support	(Yes)
`onresourcetimingbufferfull`	No support	(Yes)	?	(Yes)	?	No support	33	No support	(Yes)
`mark()`, `clearMarks()`, `measure()`, `clearMeasure()`	No support	46.0	?	42	42	10	33	No support	46.0

[1] Member prefixed with webkit have been removed or deprecated.

Properties

Events

Methods

Specifications

Browser compatibility

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