Web/API/MediaTrackConstraints/frameRate

The MediaTrackConstraints dictionary's frameRate property is a ConstrainDouble describing the requested or mandatory constraints placed upon the value of the frameRate constrainable property.

If needed, you can determine whether or not this constraint is supported by checking the value of MediaTrackSupportedConstraints.frameRate as returned by a call to MediaDevices.getSupportedConstraints(). However, typically this is unnecessary since browsers will simply ignore any constraints they're unfamiliar with.

Syntax

var constraintsObject = { frameRate: constraint };

constraintsObject.frameRate = constraint;

Value

A ConstrainDouble describing the acceptable or required value(s) for a video track's frame rate, in frames per second.

If this value is a number, the user agent will attempt to obtain media whose frame rate is as close as possible to this number given the capabilities of the hardware and the other constraints specified. Otherwise, the value of this ConstrainDouble will guide the user agent in its efforts to provide an exact match to the required frame rate (if exact is specified or both min and max are provided and have the same value) or to a best-possible value.

Example

See Example: Constraint exerciser in Capabilities, constraints, and settings for an example.

Specifications

Specification	Status	Comment
Media Capture and StreamsThe definition of 'frameRate' in that specification.	Candidate Recommendation	Initial specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`frameRate`	Chrome Full support 59	Edge Full support ≤79	Firefox Full support 50	IE No support No	Opera Full support Yes	Safari ?	WebView Android Full support 59	Chrome Android Full support 59	Firefox Android Full support 50	Opera Android ?	Safari iOS ?	Samsung Internet Android Full support 7.0

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown