demo · v139

Offline Dictation Pad

Chrome 139 adds processLocally: true to the Web Speech API — audio never leaves your device. Dictate text, toggle offline mode, and watch recognition keep working without a network connection.

Online
processing: detecting…
idle
interim results will appear here while you speak…
0
words transcribed
—
last confidence
—
processing mode

the code

const SR = window.SpeechRecognition || window.webkitSpeechRecognition;
if (!SR) { showFallback(); }

const rec = new SR();
rec.continuous = true;
rec.interimResults = true;
rec.lang = 'en-US';

// processLocally is Chrome 139+
if ('processLocally' in rec) {
  rec.processLocally = true;
  // audio stays on device — works offline
}

rec.onresult = (event) => {
  let interim = '', final = '';
  for (let i = event.resultIndex; i < event.results.length; i++) {
    const t = event.results[i][0].transcript;
    if (event.results[i].isFinal) final += t;
    else interim += t;
  }
  appendFinal(final);
  showInterim(interim);
};

rec.onerror = (e) => console.error('speech error:', e.error);
rec.start();

see also