SpeechSynthesisEvent: SpeechSynthesisEvent() constructor

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2022.

The SpeechSynthesisEvent() constructor creates a new SpeechSynthesisEvent object.

Note: A web developer doesn't typically need to call this constructor, as the browser creates these objects itself when firing events.

Syntax

new SpeechSynthesisEvent(type, options)

A string with the name of the event. It is case-sensitive and browsers set it to start, end, error, pause, resume, mark, or boundary.

An object that, in addition to the properties defined in Event(), has the following properties:

utterance: A SpeechSynthesisUtterance object, which is the speech request the event was triggered on.
charIndex Optional: The index position of the character in SpeechSynthesisUtterance.text that was being spoken when the event was triggered. Its default value is 0.
charLength Optional: The number of characters left to be spoken after the character at the charIndex position. Its default value is 0.
elapsedTime Optional: The elapsed time in seconds, after the SpeechSynthesisUtterance.text started being spoken, at which the event was triggered. Its default value is 0.
name Optional: The name associated with certain types of events: 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. It defaults to the empty string ("").

Specification
Web Speech API # dom-speechsynthesisevent-speechsynthesisevent

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`SpeechSynthesisEvent()` constructor	Chrome – Full support Chrome 71 (Release date: 2018-12-04) footnote Full support	Edge – Full support Edge 14 (Release date: 2016-08-02) footnote Full support	Firefox – Full support Firefox 49 (Release date: 2016-09-20) footnote Full support	Opera – Full support Opera 58 (Release date: 2019-01-23) footnote Full support	Safari – Full support Safari 16 (Release date: 2022-09-12) footnote Full support	Chrome Android – Full support Chrome Android 71 (Release date: 2018-12-04) footnote Full support	Firefox for Android – Full support Firefox for Android 62 (Release date: 2018-09-05) footnote Full support	Opera Android – No support Opera Android footnote No support	Safari on iOS – Full support Safari on iOS 16 (Release date: 2022-09-12) footnote Full support	Samsung Internet – Full support Samsung Internet 10 (Release date: 2019-08-22) footnote Full support	WebView Android – No support WebView Android footnote No support	WebView on iOS – Full support WebView on iOS 16 (Release date: 2022-09-12) footnote Full support

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