> ## Documentation Index
> Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Speech-to-Text REST API models

> Available speech-to-text models on the Telnyx STT REST API. Compare general, telephony, and specialty models by language, accuracy, and latency.

Your choice of `model` determines which audio formats are accepted, what `language` values are valid, and what response fields are available.

|                      | `openai/whisper-large-v3-turbo` | `openai/whisper-tiny`        | `deepgram/nova-3`                                                         |
| -------------------- | ------------------------------- | ---------------------------- | ------------------------------------------------------------------------- |
| **Default**          | Yes                             |                              |                                                                           |
| **Audio formats**    | All 10                          | All 10                       | mp3, wav only                                                             |
| **Language**         | 80+ languages, auto-detected    | 50+ languages, auto-detected | English variants only (`en`, `en-US`, `en-GB`, `en-AU`, `en-NZ`, `en-IN`) |
| **Timestamps**       | No                              | No                           | Word-level (via `model_config`)                                           |
| **Diarization**      | No                              | No                           | Yes (via `model_config`)                                                  |
| **Smart formatting** | No                              | No                           | Yes (via `model_config`)                                                  |
| **`model_config`**   | Returns 400                     | Returns 400                  | [Deepgram pass-through](/docs/voice/stt/rest-api/parameters/model-config) |

### `openai/whisper-large-v3-turbo`

Default model. Multilingual. Auto-detected if `language` omitted. See [Whisper docs](https://github.com/openai/whisper#available-models-and-languages) for the full language list. Returns text only — no timestamps regardless of `response_format`.

### `openai/whisper-tiny`

Lightweight, lowest resource usage. Multilingual (50+ languages, auto-detected). Returns text only — no timestamps.

### `deepgram/nova-3`

Highest accuracy for English. Advanced features (diarization, word timestamps, smart formatting, numerals, punctuation) available via [`model_config`](/docs/voice/stt/rest-api/parameters/model-config). Defaults `language` to `en` if omitted. Can also set `language` inside `model_config` — top-level field takes precedence. See [Deepgram language docs](https://developers.deepgram.com/docs/models-languages-overview) for details.