As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/m/gemini-3-1-flash-tts/

# Gemini 3.1 Flash TTS (preview)

Google DeepMind, Gemini 3.1 family. Status: legacy. Type: speech and audio. Released: 2026-04-15.

## How to call it

| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| Gemini API | `gemini-3.1-flash-tts-preview` | https://generativelanguage.googleapis.com/v1beta/models/gemini-3.1-flash-tts-preview:generateContent | https://ai.google.dev/gemini-api/docs/models |
| Google Cloud Text-to-Speech (Gemini-TTS) | `Gemini 3.1 Flash TTS (Preview)` |  | https://cloud.google.com/text-to-speech/pricing |

## Pricing

- Input: $1 per 1M tokens
- Output: $20 per 1M tokens
- Unit as published: per 1M tokens (USD), text in / audio out (25 audio tokens per second)
- Source: https://ai.google.dev/gemini-api/docs/pricing
- Last checked: 2026-09-29

## Specs

- Input: text
- Output: audio
- Context window: not published
- Max output: not published
- Open weights: no
- Licence: proprietary

## Where it stands

- Newer speech and audio models in the registry since its release: 61. The 5 newest:
  - NVIDIA Nemotron 3.5 Transcribe (30B-A4B) (2026-10-28) https://postcutoff.com/m/nemotron-3-5-transcribe/
  - Hy-SimulMT-30B-A3B (2026-10-22) https://postcutoff.com/m/hy-simulmt-30b-a3b/
  - Eleven Realtime v1 Max / Mini (2026-10-20) https://postcutoff.com/m/eleven-realtime-v1-max/
  - Voxtral Mini Transcribe 3 (+ Mini Transcribe Realtime 3) (2026-10-20) https://postcutoff.com/m/voxtral-mini-transcribe-3/
  - Voxtral Small Transcribe 3 (2026-10-20) https://postcutoff.com/m/voxtral-small-transcribe-3/
- Before it from Google: Gemini 3.1 Flash Live (preview) (2026-03-26) https://postcutoff.com/m/gemini-3-1-flash-live/
- After it from Google: Gemini 3.5 Live Translate (2026-06-09) https://postcutoff.com/m/gemini-3-5-live-translate/
- Closed weights; access is hosted only.

## What stands out

- Steerable expressive TTS: 'Cost-efficient, expressive, and steerable text to speech' controlled with natural-language prompts. Source: https://ai.google.dev/gemini-api/docs/changelog

## Notes

Superseded by gemini-3.8-flash-tts (GA 2026-09-22), which is cheaper at intro pricing ($0.50/$9.00). Still served as preview; also billed in Cloud TTS at the same $1/$20.

Sources: [models](https://ai.google.dev/gemini-api/docs/models), [changelog](https://ai.google.dev/gemini-api/docs/changelog), [Gemini pricing](https://ai.google.dev/gemini-api/docs/pricing), [Cloud TTS pricing](https://cloud.google.com/text-to-speech/pricing).

Model page: https://postcutoff.com/m/gemini-3-1-flash-tts/