Google Launches Gemini 3.8 Flash TTS and Flash-Lite TTS with Voice Creation from Text Prompts

Google DeepMind released two new text-to-speech models on September 23, 2026: Gemini 3.8 Flash TTS and Gemini 3.8 Flash-Lite TTS. The models are available now in Google AI Studio, the Gemini API, Gemini Enterprise, Gemini Notebook, and Google Vids.

Gemini 3.8 Flash TTS is positioned for creative direction and character design, letting users generate original voices from natural-language prompts across more than 100 languages and dialects. Gemini 3.8 Flash-Lite TTS targets high-volume use cases like dubbing and voice agents, optimized for cost efficiency at scale. Pricing not yet disclosed for either model.

Benchmark Claims

According to Google, Gemini 3.8 Flash TTS holds the #1 overall spot on Hume AI's Voice Design Benchmark with a score of 71.4, and leads in accent modeling with a score of 60.8. The company also claims Gemini 3.8 Flash TTS and Flash-Lite TTS take the #1 and #2 spots, respectively, on Hume AI's Overall Quality Index. In blind human preference evaluations on Voice Arena, Google states the models rank at the top among competitors for Japanese, Brazilian Portuguese, Vietnamese, Modern Standard Arabic, Mexican Spanish, and Hindi. None of these benchmark claims have been independently verified.

What's New

The models expand voice options from 30 preset voices to what Google describes as an "infinite library" through generative voice design — users describe a voice ("a fire-breathing dragon" or "a charismatic narrator with a regional cadence") and the model generates it. Google AI Studio also ships with over 2,000 production-ready voices covering regional variants like Mexican Spanish, Quebec French, and Scots English.

Voice replication lets users recreate a vocal profile from a 30-second audio sample, gated by a consent-verification step requiring a matching verbal consent recording from the voice owner. Other features include line-by-line performance direction with acting cues, long-form generation aimed at minimizing speaker drift across hours of audio, native two-speaker scene staging for dialogue, and scripted non-verbal cues like laughs, sighs, and backchanneling interjections.

A "voice remixing" feature — letting users adjust timbre, pitch, pace, and accent of existing library voices via prompts — is listed as coming soon rather than available at launch.

Every generated audio clip is watermarked with SynthID, and outputs carry C2PA credentials for provenance tracking. Google says this is intended to keep AI-generated speech detectable and reduce misinformation risk.

The release follows other entries in Google's Gemini Audio lineup, including 3.5 Live Translate, 3.5 Transcribe, 3.8 Live, and 3.8 Live Extended Thinking, and is compared favorably by Google against its predecessor, Gemini 3.1 Flash TTS, particularly on long-form content and dual-speaker screenplay control.

What this means

Google is pushing TTS beyond fixed-voice presets toward a prompt-driven voice design workflow, competing directly with players like ElevenLabs in synthetic voice generation. The consent-verification requirement for voice cloning and mandatory SynthID watermarking signal Google is trying to get ahead of misuse concerns before regulators force the issue. The lack of published pricing makes it hard to judge whether Flash-Lite TTS actually delivers on its cost-efficiency promise for high-volume applications like dubbing and voice agents — that comparison will matter more than benchmark rankings once developers start building at scale.