PerformanceFrameTiming

PerformanceFrameTiming is an abstract interface that provides frame timing data about the browser's event loop. A frame represents the amount of work a browser does in one event loop such as processing DOM events, resizing, scrolling, rendering, CSS animations, etc.. A frame rate of 60fps (frames per second) for a 60Hz refresh rate is the target for a good responsive user experience. This means the browser should process a frame in about 16.7ms.

An application can register a PerformanceObserver for "frame" performance entry types and the observer can retrieve data about the duration of each frame event. This information can be used to help identify areas that take too long to provide a good user experience.

Properties

This interface has no properties but it extends the following PerformanceEntry properties (for "frame" performance entry types) by qualifying and constraining the properties as follows:

PerformanceEntry.entryType

Returns "frame".

PerformanceEntry.name

Returns the document's address.

PerformanceEntry.startTime

Returns the timestamp when the frame was started.

PerformanceEntry.duration

Returns a timestamp indicating the difference between the startTimes of two successive frames.

Methods

This interface has no methods.

Example

See the example in Using the Frame Timing API.

Specifications

Browser compatibility

[1] See Chrome bug 120796.

[2] See bug 1158032.

See also

• PerformanceObserver
• Frame Rate (Firefox Performance Tool)
• Frame Timing (Overview)
• Using the Frame Timing API