Performance

The Performance interface provides access to performance-related information for the current page. It's part of the High Resolution Time API, but is enhanced by the Performance Timeline API, the Navigation Timing API, the User Timing API, and the Resource Timing API.

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

Properties

The Performance interface doesn't inherit any properties.

Performance.navigation Read only Not available to workers

A PerformanceNavigation object that provides useful context about the operations included in the times listed in timing, including whether the page was a load or a refresh, how many redirections occurred, and so forth.

Performance.timing Read only Not available to workers

A PerformanceTiming object containing latency-related performance information

performance.memory

A non-standard extension added in Chrome, this property provides an object with basic memory usage information. You should not use this non-standard API.

Performance.timeOrigin Read only

Returns the high resolution timestamp of the start time of the performance measurement.

Event handlers

Performance.onresourcetimingbufferfull

An EventTarget which is a callback that will be called when the resourcetimingbufferfull event is fired.

Methods

The Performance interface doesn't inherit any methods.

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 number 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

Browser compatibility

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