
Seed ASR 2.0 API by ByteDance
BytePlus Seed Speech recording-file recognition (ASR 2.0): transcribe an audio file to text with punctuation, ITN, sentence segmentation, speaker diarization, and 51-language support.
Seed ASR 2.0 is developed by ByteDance. Atlas Cloud (operated by Atlas Cloud AI LLC) provides access to it and does not own it. All trademarks belong to their respective owners.
Seed ASR 2.0 (Recording-File Recognition)
Transcribe an audio file to text with punctuation, ITN, sentence segmentation, speaker diarization, and 51-language support.
🌟 Key Features
🗣 High-Accuracy Transcription
State-of-the-art recognition tuned for real-world recordings.
🌍 51 Languages
Auto-detects Chinese/English/dialects, or pin a language code.
🎯 Rich Output
Punctuation, inverse text normalization, per-word timestamps, speaker labels.
📻 Far-Field Optimized
Robust to meeting-room and call-center audio.
⚙️ Parameters
| Parameter | Required | Description |
|---|---|---|
audio_url* | ✅ | Audio file URL or Base64. Formats: wav/mp3/ogg/raw. |
format | ⬜ | Audio format: mp3 (default) / wav / ogg / raw. |
language | ⬜ | Language code (e.g. en-US, yue-CN); empty = auto (CN/EN/dialects). 51 languages. |
enable_itn | ⬜ | Inverse text normalization. Default true. |
enable_punc | ⬜ | Add punctuation. Default false. |
enable_ddc | ⬜ | Semantic smoothing. Default false. |
enable_speaker_info | ⬜ | Speaker diarization. Default false. |
show_utterances | ⬜ | Per-word timestamps in stt_result.words. Default false. |
context | ⬜ | Inline hotwords — no table needed. JSON string: {"hotwords":[{"word":"YourTerm"}]}. See below. |
boosting_table_name | ⬜ | Server-side hotword table name (provisioned by Atlas). |
correct_table_name | ⬜ | Server-side correction table name (wrong→right replacement, provisioned by Atlas). |
🔥 Hotwords & Correction
Two ways to improve recognition of product names, people, and domain terms:
1. Inline via context (recommended — self-service, per request):
{ "audio_url": "https://…/meeting.mp3", "context": "{\"hotwords\":[{\"word\":\"Zylophex\"},{\"word\":\"AtlasCloud\"}]}" }
⚠️ context must be a JSON string exactly as above. Plain text (non-JSON) makes the task fail; unrecognized JSON keys are silently ignored.
2. Server-side tables via boosting_table_name / correct_table_name:
for large or stable word lists. Tables live in the service account — send Atlas your word list and we provision the table and hand back its name. ⚠️ A nonexistent table name is silently ignored (the task still succeeds), so use the exact name we give you.
📤 Output
outputs[0] contains the recognized transcript text.
stt_result carries the structured result: text, duration (seconds), and — with show_utterances=true — words[] with per-word start/end timestamps in seconds (plus speaker_id when diarization is on).
🎯 Use Cases
- Meeting & Interview Transcription — turn recordings into searchable text.
- Media Subtitling — transcribe podcasts/videos with timestamps.
- Voice Analytics — call-center QA, speaker diarization.
- Multilingual Content — transcribe across 51 languages.














