Introduction to Gemini 3.1 Flash TTS
Gemini 3.1 Flash TTS is the latest text-to-speech model developed by Google. It delivers improved controllability, expressivity, and quality, empowering developers, enterprises, and everyday users to build the next generation of AI-speech applications. The model is now available across Google products, including Google AI Studio and Vertex AI.
The Gemini 3.1 Flash TTS model introduces a high level of controllability by allowing you to steer the delivery using 200+ audio tags. These tags enable you to change the expression, pacing, and delivery of the speech output. The model also supports 70+ languages and uses SynthID watermarking to identify AI-generated audio.
Gemini 3.1 Flash TTS has been positioned in the ‘most attractive quadrant’ by Artificial Analysis for its ideal blend of high-quality speech generation and low cost. The model is available in preview on Vertex AI and can be used by developers, enterprise teams, and Workspace users.
Features of Gemini 3.1 Flash TTS
Gemini 3.1 Flash TTS has several features that make it an attractive option for developers and enterprises. The model supports 70+ languages, making it a versatile option for global applications. The SynthID watermarking feature enables the identification of AI-generated audio, which is essential for preventing misuse.
The model also introduces audio tags, which enable developers to steer the delivery of the speech output. These tags can be used to change the expression, pacing, and delivery of the speech output, giving developers granular control over the AI voice.
Gemini 3.1 Flash TTS is available in preview on Vertex AI and can be used by developers, enterprise teams, and Workspace users. The model is also available on Google AI Studio, which provides a dedicated audio playground for testing the controls.
Technical Details of Gemini 3.1 Flash TTS
Gemini 3.1 Flash TTS is based on the Gemini 3 Pro model and is designed specifically for generating speech from text inputs. The model uses a multimodal approach, supporting audio alongside other modalities such as text, images, and video.
The model introduces a high level of controllability by allowing you to steer the delivery using 200+ audio tags. These tags enable you to change the expression, pacing, and delivery of the speech output. The model also supports 70+ languages and uses SynthID watermarking to identify AI-generated audio.
Gemini 3.1 Flash TTS has been positioned in the ‘most attractive quadrant’ by Artificial Analysis for its ideal blend of high-quality speech generation and low cost. The model is available in preview on Vertex AI and can be used by developers, enterprise teams, and Workspace users.

Use Cases for Gemini 3.1 Flash TTS
Gemini 3.1 Flash TTS has several use cases, including accessibility, audiobooks, and enterprise applications. The model can be used to generate high-quality speech output for various applications, such as voice assistants, chatbots, and virtual reality experiences.
The model’s support for 70+ languages makes it an attractive option for global applications. The SynthID watermarking feature enables the identification of AI-generated audio, which is essential for preventing misuse.
Gemini 3.1 Flash TTS is available in preview on Vertex AI and can be used by developers, enterprise teams, and Workspace users. The model is also available on Google AI Studio, which provides a dedicated audio playground for testing the controls.
70+
supported languages
200+
audio tags
Comparison of Gemini 3.1 Flash TTS with other models
Comparison of Gemini 3.1 Flash TTS with other models
| Component | Open / This Approach | Proprietary Alternative |
|---|---|---|
| Language support | 70+ languages | Limited language support |
| Audio tags | 200+ audio tags | Limited audio tags |
🔑 Key Takeaway
Gemini 3.1 Flash TTS is a powerful tool for generating high-quality speech output with granular control over the AI voice. The model’s support for 70+ languages and 200+ audio tags makes it an attractive option for developers and enterprises.
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