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Window: speechSynthesis property

The speechSynthesis read-only property of the Window object returns a SpeechSynthesis object, which is the entry point into using Web Speech API speech synthesis functionality.

Value

A SpeechSynthesis object.

Examples

In our basic Speech synthesizer 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.

js

const synth = window.speechSynthesis;

const inputForm = document.querySelector("form");
const inputTxt = document.querySelector("input");
const voiceSelect = document.querySelector("select");

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

  for (const voice of voices) {
    const option = document.createElement("option");
    option.textContent = `${voice.name} (${voice.lang})`;

    if (voice.default) {
      option.textContent += " — DEFAULT";
    }

    option.setAttribute("data-lang", voice.lang);
    option.setAttribute("data-name", voice.name);
    voiceSelect.appendChild(option);
  }
}

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

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

  const utterThis = new SpeechSynthesisUtterance(inputTxt.value);
  const selectedOption =
    voiceSelect.selectedOptions[0].getAttribute("data-name");
  utterThis.voice = voices.find((v) => v.name === selectedOption);
  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 14 49 No 20 7 No 33 49 No 7 2.0

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Window/speechSynthesis