> ## 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.

# Telnyx native TTS provider

> Overview of Telnyx native text-to-speech models, comparing latency, quality, language coverage, and expressive control for the TTS REST API.

## Selecting Telnyx

Telnyx is the **default provider**. If you don't specify a provider, you get Telnyx.

**WebSocket:**

```
wss://api.telnyx.com/v2/text-to-speech/speech?voice=Telnyx.NaturalHD.astra
```

**REST:**

```bash theme={null}
curl --request POST \
  --url https://api.telnyx.com/v2/text-to-speech \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "text": "Hello.",
  "voice": "Telnyx.NaturalHD.astra"
}'
```

***

## Models

| Model                                                   | Latency | Quality | Languages     | Voice Source              | WebSocket | REST |
| ------------------------------------------------------- | ------- | ------- | ------------- | ------------------------- | --------- | ---- |
| [Natural](/docs/voice/tts/providers/telnyx/natural)     | Low     | Good    | English       | Pre-built (Rime Mist)     | Yes       | Yes  |
| [NaturalHD](/docs/voice/tts/providers/telnyx/naturalhd) | Low     | Better  | 9 languages   | Pre-built (Rime Arcana)   | Yes       | Yes  |
| [KokoroTTS](/docs/voice/tts/providers/telnyx/kokoro)    | Lowest  | Good    | 5 languages   | Pre-built                 | Yes       | Yes  |
| [Qwen3TTS](/docs/voice/tts/providers/telnyx/qwen3)      | Medium  | High    | 11 languages  | Cloned (Voice Design Lab) | Yes       | Yes  |
| [Ultra](/docs/voice/tts/providers/telnyx/ultra)         | Lowest  | Highest | 44 languages  | Pre-built                 | **No**    | Yes  |
| [Grok](/docs/voice/tts/providers/telnyx/grok)           | Higher  | High    | 20+ languages | Pre-built                 | Voice AI  | Yes  |

<Warning>
  **Ultra** is REST-only, not available over public WebSocket. Grok is available for Voice AI Assistants and direct REST TTS calls.
</Warning>

***

Browse all available voices via the [Voices API](https://developers.telnyx.com/api-reference/text-to-speech-commands/list-available-voices) or the [Voice Design Lab](https://portal.telnyx.com/#/app/ai/voice-design-lab).