Speech to Text
Built from the ground up for ultra low latency streaming. Real world telephony support. Free to try now.
Three ways to transcribe
Instant
StreamingLive transcription. Words arrive as they are spoken, each with its own timestamp.
Demand
StreamingStream audio live, then tell the service when the audio is complete and receive the finalized transcript on demand.
Transcribe
Non-streamingSend recorded audio and get the whole transcript back at once.
Capabilities
Ultra low latency
Words return the moment they are decoded.
Word-level timestamps
Every word carries start and end times, in every mode.
Telephony codecs
linear16, mulaw, alaw, G.722, and Opus at 8 or 16 kHz.
PII redaction
Redact sensitive spans from finalized transcripts before they leave the service.
Keyword boosting
Bias recognition toward the names, products, and phrases that matter to your application.
Every word is final
Output is append-only, no interim results, no revision. What lands stays.
See it for yourself
Speak into the live demo and watch your words appear. No account needed.
About this experiment
Speech recognition built from the ground up for streaming. Connect a WebSocket, send audio, and transcript segments stream back word by word with per-word timestamps.
3 supported modes to support your use case:
- Instant - Stream audio in and words are transcribed as soon as confidence allows. Sub 200ms word to transcript latency in our own testing.
- Demand - Stream audio in and signal when a transcript is requested, use your own systems to detect turn boundaries, critical conversational moments, or at regular intervals.
- Transcribe - Traditional “offline” transcription mode. Upload audio in up to 5 minute segments all at once, get the whole transcript back.
Currently supporting English only for transcription.
We are also launching with this model some built in capabilities for you to try out:
- Keyword Boosting - submit with your api request a list of up to 100 keywords and we will use them to bias the models output transcriptions to help with domain specific words.
- PII Redaction - US centric PII redaction supported for Demand and Transcribe mode. We currently look for payment card numbers, Social Security numbers, phone numbers, email addresses, dates of birth, account and ticket numbers, and ZIP codes. Detected spans are filtered from the output transcriptions and can optionally be handed back separately in the response for special handling.
This model and additional features are experimental and in a Beta state, so expect some bugs and issues, and expect new features to appear regularly. Please feel free to try everything out as much as you want while we work to improve it. If you have specific feedback for the model development team please use the feedback form to submit it.
Feature support by mode
| Feature | Instant | Demand | Transcribe |
|---|---|---|---|
| Word-level timestamps | check | check | check |
| Keyword boosting | check | check | check |
| PII redaction | - | check | check |