SpeechSynthesisUtterance

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The SpeechSynthesisUtterance interface of the Web Speech API represents a speech request. It contains the content the speech service should read and information about how to read it (e.g. language, pitch and volume.)

Constructor

SpeechSynthesisUtterance.SpeechSynthesisUtterance()

Returns a new SpeechSynthesisUtterance object instance.

Properties

SpeechSynthesisUtterance also inherits properties from its parent interface, EventTarget.

SpeechSynthesisUtterance.lang

Gets and sets the language of the utterance.

SpeechSynthesisUtterance.pitch

Gets and sets the pitch at which the utterance will be spoken at.

SpeechSynthesisUtterance.rate

Gets and sets the speed at which the utterance will be spoken at.

SpeechSynthesisUtterance.text

Gets and sets the text that will be synthesised when the utterance is spoken.

SpeechSynthesisUtterance.voice

Gets and sets the voice that will be used to speak the utterance.

SpeechSynthesisUtterance.volume

Gets and sets the volume that the utterance will be spoken at.

Events

Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.

boundary

Fired when the spoken utterance reaches a word or sentence boundary. Also available via the onboundary property.

end

Fired when the utterance has finished being spoken. Also available via the onend property.

error

Fired when an error occurs that prevents the utterance from being successfully spoken. Also available via the onerror property

mark

Fired when the spoken utterance reaches a named SSML "mark" tag. Also available via the onmark property.

pause

Fired when the utterance is paused part way through. Also available via the onpause property.

resume

Fired when a paused utterance is resumed. Also available via the onresume property.

start

Fired when the utterance has begun to be spoken. Also available via the onstart property.

Examples

In our basic Speech synthesiser demo (source), we first grab a reference to the SpeechSynthesis controller using window.speechSynthesis. After defining some necessary variables, we retrieve a list of the voices available using SpeechSynthesis.getVoices() and populate a select menu with them so the user can choose what voice they want.

Inside the inputForm.onsubmit handler, we stop the form submitting with preventDefault(), use the constructor to create a new utterance instance containing the text from the text <input>, set the utterance's voice to the voice selected in the <select> element, and start the utterance speaking via the SpeechSynthesis.speak() method.

var synth = window.speechSynthesis;
var voices = synth.getVoices();

var inputForm = document.querySelector('form');
var inputTxt = document.querySelector('input');
var voiceSelect = document.querySelector('select');

for(var i = 0; i < voices.length; i++) {
  var option = document.createElement('option');
  option.textContent = voices[i].name + ' (' + voices[i].lang + ')';
  option.value = i;
  voiceSelect.appendChild(option);
}

inputForm.onsubmit = function(event) {
  event.preventDefault();

  var utterThis = new SpeechSynthesisUtterance(inputTxt.value);
  utterThis.voice = voices[voiceSelect.value];
  synth.speak(utterThis);
  inputTxt.blur();
}

Specifications

Specification
Web Speech API
# speechsynthesisutterance

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
SpeechSynthesisUtterance
33
14
49
No
21
7
No
33
62
No
7
3.0
SpeechSynthesisUtterance
33
14
49
No
21
7
No
33
62
No
7
3.0
boundary_event
33
14
49
No
21
7
No
33
The boundary event does not fire as expected. See bug 1122143.
62
No
7
3.0
end_event
33
14
49
No
21
7
No
33
62
No
7
3.0
error_event
33
14
49
No
21
7
No
33
62
No
7
3.0
lang
33
14
49
No
21
7
No
33
62
No
7
3.0
mark_event
33
14
49
No
21
7
No
33
62
No
7
3.0
onboundary
33
14
49
No
21
7
No
33
The boundary event does not fire as expected. See bug 1122143.
62
No
7
3.0
onend
33
14
49
No
21
7
No
33
62
No
7
3.0
onerror
33
14
49
No
21
7
No
33
62
No
7
3.0
onmark
33
14
49
No
21
7
No
33
62
No
7
3.0
onpause
33
14
49
No
21
7
No
33
62
No
7
3.0
onresume
33
14
49
No
21
7
No
33
62
No
7
3.0
onstart
33
14
49
No
21
7
No
33
62
No
7
3.0
pause_event
33
14
49
No
21
7
No
33
62
No
7
3.0
pitch
33
14
49
No
21
7
No
33
62
No
7
3.0
rate
33
14
49
No
21
7
No
33
62
No
7
3.0
resume_event
33
14
49
No
21
7
No
33
62
No
7
3.0
start_event
33
14
49
No
21
7
No
33
62
No
7
3.0
text
33
14
49
No
21
7
No
33
62
No
7
3.0
voice
33
14
49
No
21
7
No
33
62
No
7
3.0
volume
33
14
49
No
21
7
No
33
62
No
7
3.0

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/SpeechSynthesisUtterance