Soniox realtime streaming transcription — low-latency multilingual STT across 60+ languages with speaker diarization, per-word timestamps, and automatic language identification over a single WebSocket.
25 languages · benchmarked
Realtime Score
71.6
TTFW (P50)
1459 ms
Flicker
66.5%
Cadence
3.6/s
RTF
1.09×
Word Error Rate
12.25%
Character Error Rate
7.10%
Benchmarks Run
35
pay per second
Rate
$0.002
/min
Per-second billing. Bring your own provider key and pay your provider directly — a 5% routing fee applies (first 100 min/mo free).
Set up BYOKCost estimator
1 hour
$0.12
10 hours
$1.19
100 hours
$11.88
1,000 hours
$118.80
Billed per second of audio processed.
POST /api/v1/transcriptions
Model ID
soniox/stt-rt
Authenticate every request with your secret API key as a Bearer token. Issue a key from your dashboard.
This model also supports realtime streaming over WebSocket.
Quickstart
Upload your audio, create a job with this model, then poll the job or set a webhook_url to be notified when it completes.
Key parameters
file_path
string
required
Storage path returned by the upload step.
model
string
required
The model to run this job on.
language
string
ISO 639-1 language code. Omit to auto-detect.
diarization
boolean
Label speakers (A, B, …) in the output.
webhook_url
string
HTTPS URL notified with the result when the job completes. Delivered events are signed (X-OT-Signature).
Response
A completed job returns the transcript in the OpenTranscription Unified Schema (OTUS).
Webhooks — skip polling
We POST a signed event to your webhook_url when a job completes or fails; verify the X-OT-Signature (HMAC-SHA256, reject if older than 300 s) and dedupe on the event id, then fetch the full transcript via GET /api/v1/transcriptions/{id}.
Rate-limited per tier — see the X-RateLimit-* response headers.
Full API referenceSupported Languages
Supported Formats
Features
Soniox STT Realtime is a speech-to-text model from Soniox. It supports 25 languages and runs at $0.002/min — cheaper than most alternatives.
Its nearest benchmarked alternative is Amazon Transcribe. Best suited for live captioning and streaming transcription, multi-speaker conversations, and high-volume, cost-sensitive pipelines.