Google introduces Gemini 3.8 Flash TTS and Flash-Lite TTS for expressive speech

Google has released Gemini 3.8 Flash TTS and Gemini 3.8 Flash-Lite TTS, two text-to-speech models designed to create more expressive and controllable synthetic speech in more than 100 languages.

Leland Rechis and Alan Cowen announce the models for Google in an official blog post. Flash TTS targets projects that need custom character voices and detailed creative direction. Flash-Lite TTS is intended for high-volume use cases such as dubbing, audio production, and voice agents.

With Flash TTS, users can describe a voice in natural language. Google says prompts can specify a role, accent, and vocal qualities, allowing creators to develop voices for characters or branded narrators. The model also offers access to more than 2,000 ready-made voices, including regional variants such as Mexican Spanish, Quebec French, and Scots English.

Control for longer scripts

Both models allow users to direct delivery at the line level. Scripts can include cues for pacing, tone, dialect changes, and conversational reactions. Google says the systems can also maintain a speaker’s timbre across hours of generated audio, a feature aimed at podcasts and audiobooks.

The models support two-speaker scenes from one script, with separate voices and turn-taking. That could be useful for dialogue-heavy training materials, narrative content, and localized media.

Google also offers voice replication from a 30-second sample, provided the user has the right to use the voice. The company says it verifies consent through a matching verbal recording from the voice owner. This feature is unavailable through AI Studio in Illinois, Texas, the European Economic Area, the United Kingdom, Switzerland, and India.

Google says all audio generated by its Gemini Audio models includes an imperceptible SynthID watermark. Flash TTS and Flash-Lite TTS are available to developers through the Gemini API and Google AI Studio. Flash TTS is also rolling out in Gemini Notebook, while Flash-Lite TTS is coming to Google Vids.