Web/API/SpeechSynthesisUtterance/boundary event

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

The boundary event of the Web Speech API is fired when the spoken utterance reaches a word or sentence boundary.

Bubbles	No
Cancelable	No
Interface	SpeechSynthesisEvent
Event handler	onboundary

Examples

You can use the boundary event in an addEventListener method:

utterThis.addEventListener('boundary', function(event) { 
  console.log(event.name + ' boundary reached after ' + event.elapsedTime + ' milliseconds.');
});

Or use the onboundary event handler property:

utterThis.onboundary = function(event) {
  console.log(event.name + ' boundary reached after ' + event.elapsedTime + ' milliseconds.');
}

Specifications

Specification	Status	Comment
Web Speech APIThe definition of 'speech synthesis utterance events' in that specification.	Draft

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
boundary event Experimental'	Chrome Full support 33	Edge Full support 14	Firefox Full support 49	IE No support No	Opera Full support 21	Safari Full support 7	WebView Android No support No	Chrome Android Full support 33	Firefox Android Full support 62 Full support 62 No support 61 — 62 Disabled' Disabled' From version 61 until version 62 (exclusive): this feature is behind the media.webspeech.synth.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.	Opera Android No support No	Safari iOS Full support 7	Samsung Internet Android Full support 3.0

Legend

Full support  

Full support

No support  

No support

Experimental. Expect behavior to change in the future.'

Experimental. Expect behavior to change in the future.

User must explicitly enable this feature.'

User must explicitly enable this feature.

See also

• Web Speech API
• onboundary

SpeechSynthesisUtterance: boundary event by Mozilla Contributors is licensed under CC-BY-SA 2.5.