The MediaTrackSettings dictionary's autoGainControl property is a Boolean value whose value indicates whether or not automatic gain control (AGC) is enabled on an audio track. This lets you determine what value was selected to comply with your specified constraints for this property's value as described in the MediaTrackConstraints.autoGainControl property you provided when calling either getUserMedia() or MediaStreamTrack.applyConstraints().

Automatic gain control is a feature in which a sound source automatically manages changes in the volume of its source media to maintain a steady overall volume level. This feature is typically used on microphones, although it can be provided by other input sources as well.

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


var autoGainControl = MediaTrackSettings.autoGainControl;


A Boolean value which is true if the track has automatic gain control enabled or false if AGC is disabled.


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


Specification Status Comment
Media Capture and Streams
The definition of 'autoGainControl' in that specification.
Candidate Recommendation Initial specification.

Browser compatibilityUpdate compatibility data on GitHub

Chrome Edge Firefox Internet Explorer Opera Safari
Basic support Yes ? 55
50 — 55
Prefixed Requires the vendor prefix: moz
? Yes ?
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support ? Yes ? 55
50 — 55
Prefixed Requires the vendor prefix: moz
Yes ? ?

See also

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