Google Gemini 3.1 Flash TTS

I did the tests, oh my god, it turned out amazing.

the inline audio tags unlock something specific for interactive web apps — not just narration, but contextual feedback. building with voice input, you always want the confirmation  to sound different from the question, which meant separate prompts or post-processing hacks. being able to embed that context inline changes the design space for conversational interfaces.

Gemini 3.1 Flash TTS is Google's new text-to-speech model, now available in preview via the Gemini API, Google AI Studio, and Vertex AI.The problem:TTS APIs have always treated voice as a static output.You pick a voice, set a speed, and the model delivers a flat read.Getting expressiveness meant engineering workarounds or accepting robotic delivery.The solution:Gemini 3.1 Flash TTS introduces audio tags natural language commands embedded directly in the text input to control tone, pacing, accent, and expression mid-sentence.You can define scene context, cast multiple speakers with unique voice profiles, and export the full configuration as API code for consistent reuse across projects.What stands out:🎙 Inline audio tags mean you can shift tone, pacing, and delivery mid-sentence without re-prompting🗣 Native multi-speaker dialogue means you can cast and direct multiple characters in a single API call🌍 70+ language support with per-locale accent control means you can localise expressive speech without a separate pipeline📤 Exportable voice config means your characters and delivery style stay consistent across every projec🔒 SynthID watermarking means every output is attributable as AI-generated out of the boxWho it's for:developers and product teams building voice agents, AI dubbing tools, interactive storytelling apps, and multilingual content platforms that need expressive, controllable speech at scale.