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 compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) mozAutoGainControl 50 (50)
autoGainControl 55 (55)
No support (Yes) ?
Feature Android Android Webview Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support ? (Yes) mozAutoGainControl 50.0 (50)
autoGainControl 55.0 (55)
No support ? ? (Yes)

See also

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Contributors to this page: Sheppy
Last updated by: Sheppy,