Models
All six return segment and word timestamps. Transcription is billed per second of audio. See the model catalog or the Models API for pricing and availability.
- Qwen3-ASR is Qwen’s multilingual model. The 1.7B model is more accurate than the 0.6B. Its word timestamps come from a separate forced aligner that doesn’t cover every language: a request for word timestamps in a language it doesn’t cover returns a 400, and the same request without word timestamps succeeds.
- Whisper Large v3 Turbo is OpenAI’s multilingual model, a faster version of Whisper Large v3. Its words start with a space and carry a
probability. - Parakeet TDT 0.6B v3 is NVIDIA’s fast multilingual model, with word timestamps from the model itself. It detects the language on its own, ignores
languageandtemperature, and reportslanguageasnull. - Parakeet Ultra is Moondream’s fine-tune of Parakeet TDT 0.6B v3, more accurate at the same speed. It also ignores
languageandtemperature. - Nemotron 3.5 Transcribe is NVIDIA’s 30B mixture-of-experts model, with 4B parameters active per token. It reports
languageasnull.
Use Prime Inference
Create a Prime API key with Inference permission in the API keys guide, then send a file:-H "X-Prime-Team-ID: your-team-id", or default_headers={"X-Prime-Team-ID": "your-team-id"} in the OpenAI client. Keep API keys server-side.
Transcribe long recordings
The models transcribe recordings of several hours. An upload holds at most 23 MiB of audio, and two hours is usually 30 to 115 MB, so put long files where Prime Inference can download them, such as a signed URL from your storage provider, and sendaudio_url:
Retry-After header’s seconds.
Send long recordings to Prime Inference directly. Through OpenRouter, a transcription must finish within 60 seconds and the audio must fit in the request.