PerformanceFrameTiming

The PerformanceFrameTiming interface 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" performannce 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.

The PerformanceFrameTiming interface has no properties, no methods nor any constructors. However, it qualifies and constrains the following PerformanceEntry properties for "frame" performance entry types: name, entryType, startTime and duration.

Properties

This interface extends the following PerformanceEntry properties (for "frame" performance entry types) by qualifying and constraining the properties as follows:

PerformanceEntry.entryType

Set to "frame".

PerformanceEntry.name

Set to the document's address.

PerformanceEntry.startTime

Set to the timestamp when the frame was started.

PerformanceEntry.duration

Set to 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

Specification	Status	Comment
Frame Timing The definition of 'PerformanceFrameTiming' in that specification.	Editor's Draft	Initial definition.

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