HTMLIFrameElement.getMuted()
the muted value is available in the request.result property, and is a boolean value — true means muted, and false means unmuted.
... promise version: a promise that resolves with the muted value — a boolean where true means muted, and false means unmuted.
... example callback version: var browser = document.queryselector('iframe'); var request = browser.getmuted(); request.onsuccess = function() { if(request.result) { console.log('the browser is muted.'); } else { console.log('the browser is unmuted.'); } } promise version: var browser = document.queryselector('iframe'); browser.getmuted().then(function(muted) { if(muted) { console.log('the browser is muted.'); } else { console.log('the browser is unmuted.'); } }); specification not part of any specification.

MediaStreamTrack.muted - Web APIs
syntax const mutedflag = track.muted value a boolean which is true if the track is currently muted, or false if the track is currently unmuted.

MediaStreamTrack: unmute event - Web APIs
when the track exits the muted state—detected by the arrival of an unmuted event—the background color is restored to white.

Media Capture and Streams API (Media Stream) - Web APIs
events addtrack ended muted overconstrained removetrack started unmuted guides and tutorials the articles below provide additional guidance and how-to information that will help you learn to use the api, and how to perform specific tasks that you may wish to handle.

Establishing a connection: The WebRTC perfect negotiation pattern - Web APIs
we add an unmute event handler to the track, because the track will become unmuted once it starts receiving packets.