demo · v150

Quality Latency Tradeoff

The three quality tiers — 'command', 'dictation', 'conversation' — trade recognition latency against accuracy and model capability. Pick a tier to see its expected latency budget, word-error rate range, resource cost, and a simulated transcript that shows the kinds of errors and improvements each tier produces. Then use the decision wizard to find the right tier for your use case.

Select a quality tier

P50 Latency
80
ms
Word Error Rate
15
%
Max Utterance
10
words
Speaker Sep.
No
diarization

Simulated transcript — same audio, different quality tier

Recognition error
Punctuation / correction added
Speaker label

Speed vs accuracy across tiers

command
latency (lower = better)
accuracy (higher = better)
80ms / 85%
dictation
latency
accuracy
320ms / 95%
conversation
latency
accuracy
800ms / 97%

Decision wizard — find the right tier

1. What type of speech input does your app handle?
2. How sensitive is the user to recognition latency?
3. What is the background noise environment?
4. How important is punctuation accuracy?
Recommendation
// Chrome 150: set quality on SpeechRecognition
const sr = new SpeechRecognition();
sr.quality = 'command';      // 50-150ms, ~85% accuracy — smart home, shortcuts
sr.quality = 'dictation';    // 200-500ms, ~95% accuracy — note-taking, emails
sr.quality = 'conversation'; // 500-1200ms, ~97%, multi-speaker — meetings

// Graceful fallback: if quality not supported, the property is silently ignored
// and the browser picks its default model
if ('quality' in SpeechRecognition.prototype) {
  sr.quality = 'dictation';
}

sr.start();

see also

implementation reference

Need the exact API surface, compatibility boundaries, errors, lifecycle, and source links? Read the matching gendn reference ↗