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 MIMME 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 compatibilityUpdate compatibility data on GitHub

Chrome Edge Firefox Internet Explorer Opera Safari
Basic support 66 ? 63 ? 55 ?
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support 66 66 ? ? 55 ? ?

See also

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