file (multipart upload) and file_url (URL download).
Common
- Max size: 100 MB
- Processing: All audio is decoded, resampled to 16kHz, and mixed to mono via ffmpeg before transcription. Container format doesn’t matter as long as ffmpeg can decode it — the validated extension list is the actual restriction.
Supported Formats
| Format | distil-whisper | whisper-turbo | deepgram/nova-3 |
|---|---|---|---|
| flac | Yes | Yes | No |
| m4a | Yes | Yes | No |
| mp3 | Yes | Yes | Yes |
| mp4 | Yes | Yes | No |
| mpeg | Yes | Yes | No |
| mpga | Yes | Yes | No |
| oga | Yes | Yes | No |
| ogg | Yes | Yes | No |
| wav | Yes | Yes | Yes |
| webm | Yes | Yes | No |
file vs file_url
file | file_url | |
|---|---|---|
| Delivery | Multipart upload in request body | Server downloads from URL before transcription |
| Timeout | Request timeout | 15s download timeout |
| Auth | N/A | URL must be publicly accessible (no auth headers forwarded) |
| Validation | Same format and size checks | Same format and size checks |
file or file_url is required. Sending both returns 400.