> [!NOTE] > **Note:** `gemini-3.1-flash-tts-preview` is a legacy preview model. For new and production workloads, migrate to [Gemini 3.8 Flash TTS](https://ai.google.dev/gemini-api/docs/models/gemini-3.8-flash-tts) (`gemini-3.8-flash-tts`) or [Gemini 3.8 Flash-Lite TTS](https://ai.google.dev/gemini-api/docs/models/gemini-3.8-flash-lite-tts) (`gemini-3.8-flash-lite-tts`). See the [migration guide](https://ai.google.dev/gemini-api/docs/speech-generation#migration). 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. [Try in Google AI Studio](https://aistudio.google.com?model=gemini-3.1-flash-tts-preview) ## Documentation The Gemini 3.1 Flash TTS Preview model introduces expressive [audio tags](https://ai.google.dev/gemini-api/docs/speech-generation#controllable) for controlling narration, as well as overall improvements to naturalness, controllability, and multilinguality. Visit the [Text-to-Speech](https://ai.google.dev/gemini-api/docs/speech-generation) guide for full coverage of features and capabilities. ## gemini-3.1-flash-tts-preview | Property | Description | |---|---| | Model code | `gemini-3.1-flash-tts-preview` | | Supported data types | **Inputs** Text **Output** Audio | | Token limits^[\[\*\]](https://ai.google.dev/gemini-api/docs/tokens)^ | **Input token limit** 8,192 **Output token limit** 16,384 | | Capabilities | **[Audio generation](https://ai.google.dev/gemini-api/docs/speech-generation)** Supported **[Caching](https://ai.google.dev/gemini-api/docs/caching)** Not supported **[Code execution](https://ai.google.dev/gemini-api/docs/code-execution)** Not supported **[File search](https://ai.google.dev/gemini-api/docs/file-search)** Not Supported **[Function calling](https://ai.google.dev/gemini-api/docs/function-calling)** Not supported **[Grounding with Google Maps](https://ai.google.dev/gemini-api/docs/maps-grounding)** Not supported **[Image generation](https://ai.google.dev/gemini-api/docs/image-generation)** Not supported **[Live API](https://ai.google.dev/gemini-api/docs/live-api)** Not supported **[Search grounding](https://ai.google.dev/gemini-api/docs/google-search)** Not supported **[Structured outputs](https://ai.google.dev/gemini-api/docs/structured-output)** Not supported **[Thinking](https://ai.google.dev/gemini-api/docs/thinking)** Not supported **[URL context](https://ai.google.dev/gemini-api/docs/url-context)** Not supported | | Consumption options | **[Batch API](https://ai.google.dev/gemini-api/docs/batch-api)** Supported **[Flex inference](https://ai.google.dev/gemini-api/docs/flex-inference)** Not supported **[Priority inference](https://ai.google.dev/gemini-api/docs/priority-inference)** Not supported | | Versions | Read the [model version patterns](https://ai.google.dev/gemini-api/docs/models/gemini#model-versions) for more details. - `gemini-3.1-flash-tts-preview` | | Latest update | April 2026 | | Model card | [Model card](https://deepmind.google/models/model-cards/gemini-3-1-flash-audio/) |