# Gemini 3.1 Flash TTS

> Google Gemini 3.1 Flash native-audio TTS via Replicate. Style instructions (separate from the spoken text) plus 30 preset voices and 40+ language/locale codes, with inline markup tags for expressive delivery ([sigh], [whispering], [shouting], etc.).

- **Provider**: replicate
- **Model ID**: google/gemini-3.1-flash-tts
- **Category**: tts_voice
- **Credits**: 299 per request
- **Pricing Type**: token_based

## API Endpoint

Base URL: https://api.core.today/v1

### Create Prediction
POST /predictions

### Get Status
GET /predictions/{job_id}

### Cancel
DELETE /predictions/{job_id}

## Authentication

Header: `X-API-Key: YOUR_API_KEY`

## Input Parameters

- `voice` (string, optional): Voice to use for speech generation (Default: `Kore`; Options: `Achernar`, `Achird`, `Algenib`, `Algieba`, `Alnilam`, `Aoede`, `Autonoe`, `Callirrhoe`, `Charon`, `Despina`, `Enceladus`, `Erinome`, `Fenrir`, `Gacrux`, `Iapetus`, `Kore`, `Laomedeia`, `Leda`, `Orus`, `Pulcherrima`, `Puck`, `Rasalgethi`, `Sadachbia`, `Sadaltager`, `Schedar`, `Sulafat`, `Umbriel`, `Vindemiatrix`, `Zephyr`, `Zubenelgenubi`)
- `language_code` (string, optional): Language for the speech output (Default: `en-US`; Options: `af-ZA`, `am-ET`, `ar-001`, `ar-EG`, `az-AZ`, `be-BY`, `bg-BG`, `bn-BD`, `ca-ES`, `ceb-PH`, `cmn-CN`, `cmn-tw`, `cs-CZ`, `da-DK`, `de-DE`, `el-GR`, `en-AU`, `en-GB`, `en-IN`, `en-US`, `es-419`, `es-ES`, `es-MX`, `et-EE`, `eu-ES`, `fa-IR`, `fi-FI`, `fil-PH`, `fr-CA`, `fr-FR`, `gl-ES`, `gu-IN`, `he-IL`, `hi-IN`, `hr-HR`, `ht-HT`, `hu-HU`, `hy-AM`, `id-ID`, `is-IS`, `it-IT`, `ja-JP`, `jv-JV`, `ka-GE`, `kn-IN`, `ko-KR`, `kok-IN`, `la-VA`, `lb-LU`, `lo-LA`, `lt-LT`, `lv-LV`, `mai-IN`, `mg-MG`, `mk-MK`, `ml-IN`, `mn-MN`, `mr-IN`, `ms-MY`, `my-MM`, `nb-NO`, `ne-NP`, `nl-NL`, `nn-NO`, `or-IN`, `pa-IN`, `pl-PL`, `ps-AF`, `pt-BR`, `pt-PT`, `ro-RO`, `ru-RU`, `sd-IN`, `si-LK`, `sk-SK`, `sl-SI`, `sq-AL`, `sr-RS`, `sv-SE`, `sw-KE`, `ta-IN`, `te-IN`, `th-TH`, `tr-TR`, `uk-UA`, `ur-PK`, `vi-VN`)
- `text` (string, **required**): The text to convert to speech. Supports markup tags like "
            "[sigh], [laughing], [whispering], [shouting], [extremely fast] for "
            "expressive delivery. Maximum 4,000 bytes.
- `prompt` (string, optional): Style instructions to control how the text is spoken. "
            "Use natural language to describe the desired tone, pace, accent, "
            'and emotion. For example: "Say this in a calm, professional tone" '
            'or "Speak with excitement and energy". Maximum 4,000 bytes. (Default: `Say the following.`)

## Example Request

```json
{
  "model": "google/gemini-3.1-flash-tts",
  "input": {
    "prompt": "your prompt here"
  }
}
```

## Response Format

```json
{
  "job_id": "abc123",
  "status": "pending",
  "provider": "replicate",
  "model": "black-forest-labs/flux-schnell",
  "created_at": "2026-01-01T00:00:00Z",
  "result": null,
  "error": null
}
```

Status values: `pending`, `processing`, `completed`, `failed`, `cancelled`

## Usage Flow

1. POST /predictions with model and input → receive job_id
2. Poll GET /predictions/{job_id} until status is `completed` or `failed`
3. Result contains output URL(s) or data

## Output Type

url

## Tags

google, gemini, text-to-speech, tts, voice-synthesis, multilingual

## Documentation

https://replicate.com/google/gemini-3.1-flash-tts


## Token Pricing

- Input: 0.298763 credits/token
- Output: 0.298763 credits/token