Gemini 3.1 Flash TTS: the next generation of expressive AI speech

Our newest audio model introduces granular audio tags that give you precise control to direct AI speech for expressive audio generation.

Gemini 3.1 Flash TTS is here, giving you improved AI speech quality and control. You can now use audio tags to adjust vocal style and pacing in over 70 languages. Test it out in Google AI Studio, Vertex AI, and Google Vids, and know that all audio is watermarked with SynthID to prevent misinformation.

Gemini 3.1 Flash TTS is here, giving you improved AI speech quality and control. You can now use audio tags to adjust vocal style and pacing in over 70 languages. Test it out in Google AI Studio, Vertex AI, and Google Vids, and know that all audio is watermarked with SynthID to prevent misinformation.

"Gemini 3.1 Flash TTS" is a new AI speech model with better control, expressiveness, and quality. This model has improved speech quality, making it sound more natural than previous versions. Audio tags let you control vocal style, pace, and delivery using natural language commands. Developers can use Google AI Studio to fine-tune voices and export settings for consistent use. Gemini 3.1 Flash TTS supports 70+ languages and uses SynthID watermarking to identify AI-generated audio.

"Gemini 3.1 Flash TTS" is a new AI speech model with better control, expressiveness, and quality.

This model has improved speech quality, making it sound more natural than previous versions.

Audio tags let you control vocal style, pace, and delivery using natural language commands.

Developers can use Google AI Studio to fine-tune voices and export settings for consistent use.

Gemini 3.1 Flash TTS supports 70+ languages and uses SynthID watermarking to identify AI-generated audio.

Gemini 3.1 Flash TTS is a new AI that makes computer speech sound more real. It lets people change how the AI talks by using special commands in the text. This AI can speak in over 70 languages and adds a hidden watermark to the audio. This helps people know it's AI-generated and not a real person.

Gemini 3.1 Flash TTS is a new AI that makes computer speech sound more real. It lets people change how the AI talks by using special commands in the text. This AI can speak in over 70 languages and adds a hidden watermark to the audio. This helps people know it's AI-generated and not a real person.

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Today, we’re introducing Gemini 3.1 Flash TTS, the latest text-to-speech model that delivers improved controllability, expressivity and quality — empowering developers, enterprises and everyday users to build the next generation of AI-speech applications.

Starting today, 3.1 Flash TTS is rolling out:

For developers in preview via the Gemini API and Google AI Studio

Improved speech quality and controllability

We’ve improved the overall speech quality of Gemini 3.1 Flash TTS, making it our most natural and expressive model to date. On the Artificial Analysis TTS leaderboard , a benchmark that captures thousands of blind human preferences, 3.1 Flash TTS achieved an impressive Elo score of 1,211.

Artificial Analysis has also positioned Gemini 3.1 Flash TTS within its “ most attractive quadrant ” for its ideal blend of high-quality speech generation and low cost. The model stands out further with native multi-speaker dialogue, support for 70+ languages, and granular creative control via natural language.

New audio tags for more expressive speech generation

3.1 Flash TTS also introduces audio tags — an intuitive way to control vocal style, pace and delivery. By embedding natural language commands directly into the text input, you can steer AI-speech output with improved levels of granularity.

You can start experimenting with these audio tags along with other updates to the developer experience in Google AI Studio with configurable controls that place the developer in the “director’s chair”:

Scene direction: Set the stage by defining the environment and providing specific dialogue instructions. This world-building context helps characters remain “in-character” and react to one another naturally across multiple turns.

Speaker-level specificity: Cast characters using unique Audio Profiles, then specify Director’s Notes to toggle pace, tone and accent. Using inline tags , speakers can pivot from these high-level settings to change expression mid-sentence.

Seamless export: Once the performance is perfected, these exact parameters can be exported as Gemini API code to ensure consistent, recognizable voices across various projects and platforms.

With these new configurations, developers can enhance precision for specific scenarios, creating memorable characters and immersive audio experiences.

Get started with high-fidelity speech generation in the Google AI Studio Playground .

Gemini 3.1 Flash TTS delivers high-fidelity speech and more precise control across more than 70 languages. These core optimizations bring advanced style, pacing and accent control to major markets — helping developers create localized, expressive speech experiences for users at global scale.

Early developer and enterprise testers are already seeing the impact of 3.1 Flash TTS, highlighting its impressive controllability and expressivity. They’ve told us how audio tags provide a new level of creative precision, transforming simple text into a high-fidelity vocal performance.

All audio generated by Gemini 3.1 Flash TTS is watermarked with SynthID. This imperceptible watermark is interwoven directly into the audio output, allowing the reliable detection of AI-generated content to help prevent misinformation. For more information on our approach to safety and responsibility, you can review the model card .

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