> ## AI Agent Context
> Get the complete documentation index at: https://aistudio.google.com/llms.txt
> Use this file to discover all available pages.
> For the full documentation in a single file, fetch: https://aistudio.google.com/llms-full.txt

# Gemini 3.1 Flash TTS (text-to-speech) preview

{% callout type="note" %}
  `gemini-3.1-flash-tts-preview` is a legacy preview model. For new and
  production workloads, migrate to
  [Gemini 3.8 Flash TTS](/docs/models/gemini-3.8-flash-tts)
  (`gemini-3.8-flash-tts`) or
  [Gemini 3.8 Flash-Lite TTS](/docs/models/gemini-3.8-flash-lite-tts)
  (`gemini-3.8-flash-lite-tts`). See the
  [migration guide](/docs/speech-generation#migration).

{% /callout %}

The Gemini 3.1 Flash TTS Preview model provides powerful, low-latency speech
generation with natural outputs, steerable prompts, and expressive audio
tags for precise narration control.

{% button href="https://aistudio.google.com?model=gemini-3.1-flash-tts-preview" variant="ais" %}Try in Google AI Studio{% /button %}

## Documentation  {% id="documentation" %}

The Gemini 3.1 Flash TTS Preview model introduces expressive [audio tags](/docs/speech-generation#controllable)
for controlling narration, as well as overall improvements to naturalness,
controllability, and multilinguality.

Visit the [Text-to-Speech](/docs/speech-generation) guide for full
coverage of features and capabilities.

## gemini-3.1-flash-tts-preview  {% id="gemini-31-flash-tts-preview" %}

{% table variant="model" %}
  * Property
  * Description

  ---

  *     {% section class="model-property" %}
  {% icon name="id_card" /%}Model code

    {% /section %}

  * `gemini-3.1-flash-tts-preview`

  ---

  *     {% section class="model-property" %}
  {% icon name="save" /%}Supported data types

    {% /section %}

  *     **Inputs** Text

    **Output** Audio


  ---

  *     {% section class="model-property" %}
  {% icon name="token_auto" /%}Token limits{% sup %}[[*]](/docs/tokens){% /sup %}

    {% /section %}

  *     **Input token limit** 8,192

    **Output token limit** 16,384


  ---

  *     {% section class="model-property" %}
  {% icon name="handyman" /%}Capabilities

    {% /section %}

  *     {% section class="three-column-grid" %}
  {% section %}
  [**Audio generation**](/docs/speech-generation)

  {% badge type="supported" /%}

  {% /section %}

  {% section %}
  [**Batch API**](/docs/batch-api)

  {% badge type="supported" /%}

  {% /section %}

  {% section %}
  [**Caching**](/docs/caching)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**Code execution**](/docs/code-execution)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**File search**](/docs/file-search)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**Function calling**](/docs/function-calling)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**Grounding with Google Maps**](/docs/maps-grounding)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**Image generation**](/docs/image-generation)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**Live API**](/docs/live-api)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**Search grounding**](/docs/google-search)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**Structured outputs**](/docs/structured-output)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**Thinking**](/docs/thinking)

  {% badge type="not-supported" /%}

  {% /section %}

  {% section %}
  [**URL context**](/docs/url-context)

  {% badge type="not-supported" /%}

  {% /section %}

    {% /section %}


  ---

  *     {% section class="model-property" %}
  {% icon name="123" /%}Versions

    {% /section %}

  *     Read the [model version patterns](/docs/models#model-versions) for more details.

    *   `gemini-3.1-flash-tts-preview`


  ---

  *     {% section class="model-property" %}
  {% icon name="calendar_month" /%}Latest update

    {% /section %}

  * April 2026

  ---

  *     {% section class="model-property" %}
  {% icon name="id_card" /%}Model card

    {% /section %}

  * [Model card](https://deepmind.google/models/model-cards/gemini-3-1-flash-audio/)

  ---

  *     {% section class="model-property" %}
  {% icon name="paid" /%}Pricing

    {% /section %}

  * [Pricing](/docs/pricing#gemini-3.1-flash-tts-preview)
{% /table %}