The Boolean property fastSeek in the MediaSessionActionDetails dictionary is an optional value which, when specified and true, indicates that the requested seekto operation is part of an ongoing series of seekto operations. Your handler should take steps to return as quickly as possible by skipping any steps of its operation which are only necessary when the seek operation is complete.

Once fastSeek is false or not present, the repeating series of seekto actions is complete and you can finalize the state of your web app or content.


let mediaSessionActionDetails = { fastSeek: shouldFastSeek };

let shouldFastSeek = mediaSessionActionDetails.fastSeek;


A Boolean which is true if the action is part of an ongoing series of seek actions which should be treated as part of an overall seek operation. If the value is false or this property isn't present, the seek is final.


Specification Status Comment
Media Session Standard
The definition of 'MediaSessionActionDetails.fastSeek' in that specification.
Draft Initial definition.

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Chrome Full support 73Edge Full support ≤79Firefox No support NoIE ? Opera No support NoSafari ? WebView Android No support NoChrome Android Full support 57Firefox Android No support NoOpera Android No support NoSafari iOS ? Samsung Internet Android Full support 7.0


Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also