The MediaTrackSupportedConstraints dictionary's autoGainControl property is a read-only Boolean value which is present (and set to true) in the object returned by MediaDevices.getSupportedConstraints() if and only if the user agent supports the autoGainControl constraint. If the constraint isn't supported, it's not included in the list, so this value will never be false.

You can access the supported constraints dictionary by calling navigator.mediaDevices.getSupportedConstraints().

The autoGainControl cconstraint indicates whether or not the browser offers the ability to automatically control the gain (volume) on media tracks; this obviously is contingent on whether or not the individual device supports automatic gain control as well; it's typically a feature provided by microphones.


autoGainSupported = supportedConstraintsDictionary["autoGainControl"];


This property is present in the dictionary (and its value is always true) if the user agent supports the autoGainControl constraint. If the property isn't present, this property is missing from the supported constraints dictionary, and you'll get undefined if you try to look at its value.


This example simply displays whether or not your browser supports the autoGainControl constraint.

let result = document.getElementById("result");

if (navigator.mediaDevices.getSupportedConstraints()["autoGainControl"]) {
    result.innerHTML = "Supported!";
} else {
    result.innerHTML = "Not supported!";



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 46 (46)
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 46.0 (46)
autoGainControl 50.0 (50)
No support ? ? (Yes)

See also

Document Tags and Contributors

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