Web/API/MediaTrackSupportedConstraints/channelCount

The MediaTrackSupportedConstraints dictionary's channelCount 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 channelCount 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().

Syntax

channelCountConstraintSupported = supportedConstraintsDictionary.channelCount;

Value

This property is present in the dictionary (and its value is always true) if the user agent supports the channelCount 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.

Example

HTML content

<div id="result">
</div>

CSS content

#result {
  font: 14px "Arial", sans-serif;
}

JavaScript content

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

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

Result

Specifications

Specification	Status	Comment
Media Capture and StreamsThe definition of 'channelCount' 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
`channelCount`	Chrome Full support 52	Edge Full support ≤79	Firefox Full support 56	IE No support No	Opera Full support Yes	Safari ?	WebView Android Full support 52	Chrome Android Full support 52	Firefox Android Full support 56	Opera Android Full support Yes	Safari iOS ?	Samsung Internet Android Full support 6.0

Legend

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