StepAudio 3 Realtime
Speech and audio
stepaudio-3-realtime-preview
Free
StepAudio 3 ASR Max / StepAudio 3 TTS
Model idstepaudio-3-asr-max
Price$0.40 per hour, speech recognition
Checked29 September 2026
Where it stands
25newer speech and audio models since its release
- NVIDIA Nemotron 3.5 Transcribe (30B-A4B)28 Oct 2026
- Hy-SimulMT-30B-A3B22 Oct 2026
- Eleven Realtime v1 Max / Mini20 Oct 2026
- Voxtral Mini Transcribe 3 (+ Mini Transcribe Realtime 3)20 Oct 2026
- Voxtral Small Transcribe 320 Oct 2026
The 5 newest are listed. All speech and audio models
- Before it from StepFun
- StepFun Step-Audio-EditX6 Nov 2025
- Weights
- Closed weights; access is hosted only.
How to call it
3 ways to use StepAudio 3 ASR Max / StepAudio 3 TTS, with the model id each provider expects.
| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| StepFun API | stepaudio-3-asr-max |
platform.stepfun.ai | |
| StepFun API | stepaudio-3-tts |
platform.stepfun.ai | |
| StepFun API (preview) | stepaudio-3-gen-preview |
platform.stepfun.ai |
Pricing
| Per hour, speech recognition | $0.40 |
|---|---|
| Per 10K characters, speech | $0.36 |
As published: “USD: stepaudio-3-asr-max $0.40/hour of audio; stepaudio-3-tts $0.36 per 10,000 characters; voice cloning $1.50/voice”.
Source: platform.stepfun.ai, checked 29 September 2026.
Specs
- Input
- Audio and text
- Output
- Text and audio
- Context window
- Not published
- Max output
- Not published
- Open weights
- No
- Licence
- Proprietary
- Released
- 15 September 2026
- Status
- Current
- Type
- Speech and audio
What stands out
What its maker marketed at launch, and what people found later, each with its source.
#1 non-streaming ASR on AA-WER
Artificial Analysis ranked StepAudio 3 ASR #1 on its AA-WER Index for non-streaming speech-to-text with 1.7% WER (StepAudio 2.5 ASR: 4.7%).
Context-aware streaming TTS
Natural, context-aware speech with low-latency streaming, natural-language control and voice cloning; 1,000-char input limit; wav/mp3/flac/opus/pcm.
Notes
Family file for the non-realtime StepAudio 3 models. Languages: zh, en, ja, ko, fr, es (non-zh/en in preview). stepaudio-3-gen-preview (speech+SFX+ambience+BGM) and stepaudio-3-music-preview are free during preview. Previous gen: stepaudio-2.5-asr ($0.022/h), stepaudio-2.5-asr-stream ($0.18/h), stepaudio-2.5-tts ($0.85/10k chars). Exact per-model release date assumed = family launch 2026-09-15.
Sources: https://platform.stepfun.ai/docs/en/guides/models/audio · https://platform.stepfun.ai/docs/en/pricing/details