Web/API/SpeechSynthesisEvent

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

The SpeechSynthesisEvent interface of the Web Speech API contains information about the current state of SpeechSynthesisUtterance objects that have been processed in the speech service.

Properties

The SpeechSynthesisEvent interface also inherits properties from its parent interface, Event.

SpeechSynthesisEvent.charIndex Read only: Returns the index position of the character in the SpeechSynthesisUtterance.text that was being spoken when the event was triggered.
SpeechSynthesisEvent.elapsedTime Read only: Returns the elapsed time in milliseconds after the SpeechSynthesisUtterance.text started being spoken that the event was triggered at.
SpeechSynthesisEvent.name Read only: Returns the name associated with certain types of events occuring as the SpeechSynthesisUtterance.text is being spoken: the name of the SSML marker reached in the case of a mark event, or the type of boundary reached in the case of a boundary event.
SpeechSynthesisEvent.utterance Read only: Returns the SpeechSynthesisUtterance instance that the event was triggered on.

Methods

The SpeechSynthesisEvent interface also inherits methods from its parent interface, Event.

Examples

utterThis.onpause = function(event) {
  var char = event.utterance.text.charAt(event.charIndex);
  console.log('Speech paused at character ' + event.charIndex + ' of "' +
  event.utterance.text + '", which is "' + char + '".');
}

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

Specifications

Specification	Status	Comment
Web Speech APIThe definition of 'SpeechSynthesisEvent' in that specification.	Draft

Browser compatibility

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
`SpeechSynthesisEvent` Experimental'	Chrome Full support 33	Edge Full support ≤18	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
`charIndex` 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
`elapsedTime` 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
`name` 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
`utterance` 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.