Generate expressive speech from text with optional multi-speaker voice configuration.
Model Overview
Gemini 3.1 Flash TTS converts text prompts into speech audio. It supports single-speaker synthesis and multi-speaker scripts where prompt line prefixes match configured speaker aliases.
Best At
- Dialogue-style text-to-speech with named speakers.
- Expressive narration controlled by natural-language style instructions.
- Speech prompts that include inline delivery cues for pacing, tone, and emotion.
Limitations / Not Good At
- Speaker aliases must match the prefixes used in the prompt.
- The single-speaker voice setting is ignored when speaker groups are configured.
- Very long or inconsistently tagged scripts may need editing before synthesis.
Ideal Use Cases
- Podcast or interview drafts with two or more named speakers.
- Narration, explainer audio, and character dialogue.
- Prototyping multilingual or expressive speech workflows from text.
Input & Output Format
- Input: required prompt, optional style instructions, optional single-speaker voice, optional language code, optional temperature, and zero or more speaker groups.
- Output: generated WAV audio returned on response.
Performance Notes
Multi-speaker synthesis is enabled only when at least one speaker group is present.