How to Use the Web Speech API in HTML5

Published in: JavaScript

The Voice Dictation app uses the Web Speech API to convert your spoken words into text. There’s a simple JavaScript API that lets you integrate Speech Recognition on any website.

The Web Speech API is currently implemented in Chrome and Firefox.

<a href="#" id="start_button" onclick="startDictation(event)">Dictate</a>

<div id="results">
<span id="final_span" class="final"></span>
<span id="interim_span" class="interim"></span>

<script type="text/javascript">
var final_transcript = '';
var recognizing = false;

if ('webkitSpeechRecognition' in window) {

var recognition = new webkitSpeechRecognition();

recognition.continuous = true;
recognition.interimResults = true;

recognition.onstart = function() {
  recognizing = true;

recognition.onerror = function(event) {

recognition.onend = function() {
  recognizing = false;

recognition.onresult = function(event) {
  var interim_transcript = '';
  for (var i = event.resultIndex; i < event.results.length; ++i) {
    if (event.results[i].isFinal) {
      final_transcript += event.results[i][0].transcript;
    } else {
      interim_transcript += event.results[i][0].transcript;
  final_transcript = capitalize(final_transcript);
  final_span.innerHTML = linebreak(final_transcript);
  interim_span.innerHTML = linebreak(interim_transcript);


var two_line = /\n\n/g;
var one_line = /\n/g;
function linebreak(s) {
return s.replace(two_line, '<p></p>').replace(one_line, '<br>');

function capitalize(s) {
return s.replace(s.substr(0,1), function(m) { return m.toUpperCase(); });

function startDictation(event) {
if (recognizing) {
final_transcript = '';
recognition.lang = 'en-US';
final_span.innerHTML = '';
interim_span.innerHTML = '';
Published in: JavaScript

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Amit Agarwal

Amit Agarwal is a Google Developer Expert in Google Workspace and Google Apps Script. He holds an engineering degree in Computer Science (I.I.T.) and is the first professional blogger in India. He is the developer of Mail Merge for Gmail and Document Studio. Read more on Lifehacker and YourStory

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