SpeechSynthesis

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

The SpeechSynthesis interface of the Web Speech API is the controller interface for the speech service; this can be used to retrieve information about the synthesis voices available on the device, start and pause speech, and other commands besides.

Properties

SpeechSynthesis also inherits properties from its parent interface, EventTarget.

SpeechSynthesis.paused Read only

A boolean value that returns true if the SpeechSynthesis object is in a paused state.

SpeechSynthesis.pending Read only

A boolean value that returns true if the utterance queue contains as-yet-unspoken utterances.

SpeechSynthesis.speaking Read only

A boolean value that returns true if an utterance is currently in the process of being spoken — even if SpeechSynthesis is in a paused state.

Methods

SpeechSynthesis also inherits methods from its parent interface, EventTarget.

SpeechSynthesis.cancel()

Removes all utterances from the utterance queue.

SpeechSynthesis.getVoices()

Returns a list of SpeechSynthesisVoice objects representing all the available voices on the current device.

SpeechSynthesis.pause()

Puts the SpeechSynthesis object into a paused state.

SpeechSynthesis.resume()

Puts the SpeechSynthesis object into a non-paused state: resumes it if it was already paused.

SpeechSynthesis.speak()

Adds an utterance to the utterance queue; it will be spoken when any other utterances queued before it have been spoken.

Events

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

voiceschanged

Fired when the list of SpeechSynthesisVoice objects that would be returned by the SpeechSynthesis.getVoices() method has changed. Also available via the onvoiceschanged property.

Examples

First, a simple example:

let utterance = new SpeechSynthesisUtterance("Hello world!");
speechSynthesis.speak(utterance);

Now we'll look at a more fully-fledged example. In our Speech synthesiser demo, 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(), create a new SpeechSynthesisUtterance 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 inputForm = document.querySelector('form');
var inputTxt = document.querySelector('.txt');
var voiceSelect = document.querySelector('select');

var pitch = document.querySelector('#pitch');
var pitchValue = document.querySelector('.pitch-value');
var rate = document.querySelector('#rate');
var rateValue = document.querySelector('.rate-value');

var voices = [];

function populateVoiceList() {
  voices = synth.getVoices();

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

    if(voices[i].default) {
      option.textContent += ' -- DEFAULT';
    }

    option.setAttribute('data-lang', voices[i].lang);
    option.setAttribute('data-name', voices[i].name);
    voiceSelect.appendChild(option);
  }
}

populateVoiceList();
if (speechSynthesis.onvoiceschanged !== undefined) {
  speechSynthesis.onvoiceschanged = populateVoiceList;
}

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

  var utterThis = new SpeechSynthesisUtterance(inputTxt.value);
  var selectedOption = voiceSelect.selectedOptions[0].getAttribute('data-name');
  for(var i = 0; i < voices.length ; i++) {
    if(voices[i].name === selectedOption) {
      utterThis.voice = voices[i];
    }
  }
  utterThis.pitch = pitch.value;
  utterThis.rate = rate.value;
  synth.speak(utterThis);

  inputTxt.blur();
}

Specifications

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
SpeechSynthesis
33
≤18
49
No
21
7
No
33
62
No
7
3.0
cancel
33
14
49
No
21
7
No
33
62
No
7
3.0
getVoices
33
14
49
No
21
7
No
33
62
No
7
3.0
onvoiceschanged
33
14
49
No
No
No
No
33
62
No
No
3.0
pause
33
14
49
No
21
7
No
33
In Android, pause() ends the current utterance. pause() behaves the same as cancel().
62
In Android, pause() ends the current utterance. pause() behaves the same as cancel().
No
7
3.0
In Android, pause() ends the current utterance. pause() behaves the same as cancel().
paused
33
14
49
No
21
7
No
33
62
No
7
3.0
pending
33
14
49
No
21
7
No
33
62
No
7
3.0
resume
33
14
49
No
21
7
No
33
62
No
7
3.0
speak
33
14
49
No
21
7
No
33
62
No
7
3.0
speaking
33
14
49
No
21
7
No
33
62
No
7
3.0
voiceschanged_event
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/SpeechSynthesis