| name | gemini-tts |
| description | Referencia tecnica de Gemini TTS — voces disponibles, audio tags, formato multi-speaker, framework de prompting y limitaciones. Consulta al planificar voiceover o generar audio. |
Gemini TTS Reference
Technical reference for the Gemini TTS model (gemini-3.1-flash-tts-preview).
Available Voices (30)
| Voice | Character | Best for |
|---|
| Orus | Warm, didactic | Tutorials, explainers |
| Kore | Corporate, professional | Business content |
| Puck | Energetic, young | Social media, shorts |
| Charon | Deep, authoritative | Narration, serious topics |
| Leda | Soft, feminine | Calm, intimate content |
| Zephyr | Neutral, calm | General purpose |
| Aoede | Bright, musical | Creative, upbeat content |
| Fenrir | Bold, dramatic | Impact moments, trailers |
| Achernar | Clear, precise | Technical content |
| Algieba | Warm, resonant | Storytelling |
| Autonoe | Gentle, nurturing | Educational, kids |
| Callirrhoe | Melodic, expressive | Entertainment |
| Despina | Crisp, articulate | News-style delivery |
| Erinome | Smooth, sophisticated | Premium, luxury |
| Gacrux | Gruff, textured | Character voices |
| Iapetus | Steady, reliable | Instructional |
| Keid | Light, airy | Lifestyle content |
| Laomedeia | Rich, commanding | Leadership content |
| Pulcherrima | Elegant, refined | Formal presentations |
| Rasalgethi | Deep, thoughtful | Philosophical content |
| Sadachbia | Friendly, approachable | Conversational |
| Sadaltager | Energetic, motivational | Sports, fitness |
| Schedar | Mature, wise | Documentary style |
| Sulafat | Playful, quirky | Fun, casual content |
| Umbriel | Mysterious, atmospheric | Suspense, sci-fi |
| Vindemiatrix | Confident, assertive | Sales, persuasion |
| Enceladus | Warm, inviting | Welcome messages |
| Thalassa | Serene, flowing | Meditation, relaxation |
| Proteus | Versatile, adaptive | Multi-genre |
| Dione | Bright, cheerful | Celebrations, promos |
Audio Tags (Transcript Tags)
Inline modifiers in brackets that control delivery. The TTS engine interprets them as performance directions — no code changes needed, just include them in the text.
Emotion tags
[amazed] This is incredible!
[excited] We just launched the new feature!
[sarcastic] Oh great, another meeting.
[tired] It's been a long day...
[whispers] This is a secret.
[cheerful] Welcome to the show!
[serious] Let's talk about security.
[sad] Unfortunately, the project was cancelled.
Action tags
[laughs] That's hilarious!
[sighs] Here we go again.
[gasp] I can't believe it!
[cough] Excuse me.
[giggles] You're funny.
Delivery tags
[very fast] This part needs to be quick!
[very slow] Let... that... sink... in.
[shouting] ATTENTION EVERYONE!
[softly] Just between us...
Creative tags
[like a radio announcer] Coming up next...
[like a sports commentator] And he scores!
Rules for audio tags
- Place tag BEFORE the text it modifies
- Tags apply until the next tag or end of text
- For non-English text, use English tags:
[whispers] Este es un secreto
- Use sparingly — 1-2 tags per scene max for natural delivery
- Test with short clips before generating full scenes
Multi-Speaker Support
Up to 2 speakers per scene. Uses multi_speaker_voice_config API instead of voice_config.
Config format
{
"voiceover": {
"enabled": true,
"provider": "gemini",
"language": "es-ES",
"speakers": [
{ "name": "Ana", "voiceId": "Leda" },
{ "name": "Carlos", "voiceId": "Orus" }
],
"scenes": {
"0": "Ana: Bienvenidos al tutorial.\nCarlos: Hoy hablamos de Docker.",
"1": { "text": "Ana: [excited] Veamos el ejemplo.\nCarlos: Abre tu terminal." }
}
}
}
When speakers is present, multi-speaker mode activates. When absent, single-speaker mode uses voiceId.
Rules
- Exactly 2 speakers (API limit)
- Speaker names in text MUST match names in
speakers config
- Each speaker gets a different voice — choose contrasting timbres (e.g., Orus + Leda, Charon + Puck)
- Audio tags work inside multi-speaker text
- Output is a single audio stream per scene (one MP3 with both voices)
Prompting Framework
For best quality, structure text with:
- Audio Profile — who is speaking (name, role, personality)
- Scene — environmental context (studio, outdoors, intimate)
- Director's Notes — style guidance (pacing, accent, energy)
- Transcript — the actual text to speak
For single-speaker, embed guidance via audio tags. For multi-speaker, speaker names provide audio profile context.
Limitations
- Max 32k token context per request
- No streaming — full generation before response
- Quality drifts on outputs > ~2 minutes
- Split longer narrations into per-scene chunks (pipeline default)
- Rate limits: 3 retries with exponential backoff (15s, 30s, 45s)