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

# Models

> Compare Supertone TTS models by quality, latency, supported languages, voice settings, and additional features to choose the best model for your use case.

## Model Summary

| Model                   | Positioning               | Languages | Voice Settings | Extra Features                           |
| ----------------------- | ------------------------- | --------- | -------------- | ---------------------------------------- |
| **Sona Speech 1**       | Legacy flagship           | 3         | Advanced       | Phonemes with Timestamp, Streaming       |
| **Sona Speech 2**       | Latest flagship           | 23        | Advanced       | Phonemes with Timestamp, Normalized Text |
| **Sona Speech 2 Flash** | Lightweight / low-latency | 23        | Core           | Phonemes with Timestamp, Normalized Text |
| **Supertonic API 1**    | Ultra-lightweight         | 5         | Minimal        | –                                        |

***

## Supported Languages

| Model                   | Languages                                                                                  |
| ----------------------- | ------------------------------------------------------------------------------------------ |
| **Sona Speech 1**       | en, ko, ja                                                                                 |
| **Sona Speech 2**       | en, ko, ja, bg, cs, da, el, es, et, fi, hu, it, nl, pl, pt, ro, ar, de, fr, hi, id, ru, vi |
| **Sona Speech 2 Flash** | en, ko, ja, bg, cs, da, el, es, et, fi, hu, it, nl, pl, pt, ro, ar, de, fr, hi, id, ru, vi |
| **Supertonic API 1**    | en, ko, ja, es, pt                                                                         |

***

## Supported Voice Settings

| Model                   | Voice Settings                                                                                                       |
| ----------------------- | -------------------------------------------------------------------------------------------------------------------- |
| **Sona Speech 1**       | `pitch_shift`, `pitch_variance`, `speed`, `duration`, `similarity`, `text_guidance`                                  |
| **Sona Speech 2**       | `pitch_shift`, `pitch_variance`, `speed`, `duration`, `similarity`, `text_guidance`, `subharmonic_amplitude_control` |
| **Sona Speech 2 Flash** | `pitch_shift`, `pitch_variance`, `speed`, `duration`                                                                 |
| **Supertonic API 1**    | `speed`                                                                                                              |

***

## Additional Features

| Model                   | Supported Features                    |
| ----------------------- | ------------------------------------- |
| **Sona Speech 1**       | `include_phonemes`, `streaming`       |
| **Sona Speech 2**       | `include_phonemes`, `normalized_text` |
| **Sona Speech 2 Flash** | `include_phonemes`, `normalized_text` |
| **Supertonic API 1**    | –                                     |

***

## Quick Selection Guide

| If you need…                             | Recommended Model       |
| ---------------------------------------- | ----------------------- |
| Legacy compatibility or streaming output | **Sona Speech 1**       |
| Best overall speech quality              | **Sona Speech 2**       |
| Low-latency & lightweight inference      | **Sona Speech 2 Flash** |
| Minimal configuration & fastest setup    | **Supertonic API 1**    |

***

## Related Documentation

<CardGroup cols={2}>
  <Card title="Text-to-Speech Guide" icon="comment" href="/en/user-guide/text-to-speech">
    Detailed usage, parameters, and audio output formats.
  </Card>

  <Card title="API Reference" icon="book-open" href="/en/api-reference/introduction">
    Complete API specification and request examples.
  </Card>
</CardGroup>