Google has officially introduced Gemini 3.1 Flash-TTS, its latest and most advanced text-to-speech model. Designed for high-fidelity audio generation, the model focuses on providing developers and enterprises with unprecedented levels of controllability and expressiveness across more than 70 languages.

Audio Tags: The "Director's Chair" for Speech

The standout feature of Gemini 3.1 Flash-TTS is the introduction of audio tags. These are natural language commands embedded directly into the text input that allow users to steer the AI's delivery with granular precision.

• Dynamic Style & Pacing: Use tags to adjust vocal style, tone, and delivery speed mid-sentence.

• Scene Direction: Developers can set "Director's Notes" to world-build context, ensuring characters stay in character and react naturally during multi-speaker dialogues.

• Speaker Specificity: Cast distinct characters using unique Audio Profiles and toggle accents or expressions for a more immersive experience.

Industry-Leading Performance

According to the Artificial Analysis TTS leaderboard, Gemini 3.1 Flash-TTS achieved an impressive Elo score of 1,211, placing it among the most natural-sounding models available. It is positioned in the "most attractive quadrant" of the market due to its high-quality output paired with low operational costs.

Enterprise and Developer Access

• Gemini API & Google AI Studio: Currently available in preview for developers to experiment with voices and export configurations.

• Vertex AI: Available in preview for enterprises looking to integrate expressive speech into applications.

• Google Workspace: Integrated into Google Vids to help users create engaging video content with professional voiceovers.

Safety and Watermarking

To help prevent misinformation and clearly identify AI-generated content, every audio output from Gemini 3.1 Flash-TTS is imperceptibly watermarked with SynthID. This technology is woven directly into the audio data, allowing for reliable detection of AI speech without affecting the listening quality.

This model provides a powerful new toolset for building everything from accessible reading apps to immersive, multi-character gaming experiences and localized voice assistants.