RTCDTMFToneChangeEvent: tone property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2020.

The read-only property RTCDTMFToneChangeEvent.tone returns the DTMF character which has just begun to play, or an empty string (""). if all queued tones have finished playing (that is, RTCDTMFSender.toneBuffer is empty).

Value

A string with the DTML character playing, or the empty string.

Example

This example establishes a handler for the tonechange event which updates an element to display the currently playing tone in its content, or, if all tones have played, the string "<none>".

js
dtmfSender.ontonechange = (ev) => {
  let tone = ev.tone;
  if (tone === "") {
    tone = "&lt;none&gt;";
  }

  document.getElementById("playingTone").innerText = tone;
};

Specifications

Specification
WebRTC: Real-Time Communication in Browsers
# dom-rtcdtmftonechangeevent-tone

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
tone
Chrome – Full support
Chrome 27 (Release date: 2013-05-21)
footnote Full support
Edge – Full support
Edge 12 (Release date: 2015-07-29)
footnote Full support
Firefox – Full support
Firefox 52 (Release date: 2017-03-07)
footnote Full support
Opera – Full support
Opera 15 (Release date: 2013-07-02)
footnote Full support
Safari – Full support
Safari 13.1 (Release date: 2020-03-24)
footnote Full support
Chrome Android – Full support
Chrome Android 27 (Release date: 2013-05-22)
footnote Full support
Firefox for Android – Full support
Firefox for Android 52 (Release date: 2017-03-07)
footnote Full support
Opera Android – Full support
Opera Android 15 (Release date: 2013-07-08)
footnote Full support
Safari on iOS – Full support
Safari on iOS 13.4 (Release date: 2020-03-24)
footnote Full support
Samsung Internet – Full support
Samsung Internet 1.5 (Release date: 2013-09-25)
footnote Full support
WebView Android – Full support
WebView Android 4.4 (Release date: 2013-12-09)
footnote Full support
WebView on iOS – Full support
WebView on iOS 13.4 (Release date: 2020-03-24)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also