The MediaCapabilities.decodingInfo() method, part of the Media Capabilities API, returns a promise with the tested media configuration's mediaCapabilitiesInfo; this contains the three Boolean properties supported, smooth, and powerefficient, which describe whether decoding the media described would be supported, smooth, and powerefficient.




A valid MediaDecodingConfiguration dictionary containing a valid media decoding type of file or media-source and a valid media configuration: either an AudioConfiguration or a VideoConfiguration.

Return value

A Promise fulfilling with a MediaCapabilitiesInfo interface containing three Boolean attributes:

  • supported
  • smooth
  • powerEfficient


A TypeError is raised if the MediaConfiguration passed to the decodingInfo() method is invalid, either because the type is not video or audio, the contentType is not a valid codec MIME type, the media decoding configuration is not a valid value for the media decoding type, or any other error in the media configuration passed to the method, including omitting values required in the media decoding configuration.


//Create media configuration to be tested
const mediaConfig = {
    type : 'file', // or 'media-source'
    audio : {
        contentType : "audio/ogg", // valid content type 
        channels : 2,     // audio channels used by the track
        bitrate : 132700, // number of bits used to encode 1s of audio 
        samplerate : 5200 // number of audio samples making up that 1s. 

// check support and performance
navigator.mediaCapabilities.decodingInfo(mediaConfig).then(result => {
    console.log('This configuration is ' +
        (result.supported ? '' : 'not ') + 'supported, ' +
        (result.smooth ? '' : 'not ') + 'smooth, and ' +
        (result.powerEfficient ? '' : 'not ') + 'power efficient.')


Specification Status Comment
Media Capabilities
The definition of 'decodingInfo()' in that specification.
Draft Initial definition

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Chrome Full support 66Edge Full support ≤79Firefox Full support 63IE ? Opera Full support 55Safari ? WebView Android Full support 66Chrome Android Full support 66Firefox Android Full support 63Opera Android Full support 48Safari iOS ? Samsung Internet Android Full support 9.0


Full support
Full support
Compatibility unknown
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also