Gemini 3.1 Flash TTS Preview

gemini-3.1-flash-tts-preview

Gemini 3.1 Flash TTS Preview is Google's next-generation text-to-speech model, delivering a major upgrade over Gemini 2.5 Flash TTS. It converts text into natural audio across 70+ languages, with significantly expanded language coverage and improved quality. The model introduces 200+ inline audio control tags (e.g., [whispers], [laughs], [excited]) for fine-grained control over emotion, tone, and pacing, along with support for two speakers with independent voice and style settings. It outputs 24 kHz / 16-bit PCM audio, includes SynthID watermarking, and supports a 32K token context window. Designed for expressive and controllable voice generation, it is well suited for dialogue systems, storytelling, character-driven content, and advanced audio production workflows.

Context: 8.2K tokens
Endpoint

Service Status

Status information temporarily unavailable

Apertis cannot confirm the current service state. This is not a report that the model is down.

Get API Key Compare

Pricing

Input$27.50 / 1M

Output$0 / 1M

Cache Write (5m)Not applicable

Cache Write (1h)Not applicable

Cache ReadNot applicable

Web Search$0 / 1M

Quick Start

Select an endpoint and copy a working example for this model.

Endpoint

python

from openai import OpenAI client = OpenAI(    api_key="YOUR_API_KEY",    base_url="https://api.apertis.ai/v1") response = client.chat.completions.create(    model="gemini-3.1-flash-tts-preview",    messages=[        {"role": "user", "content": "Hello!"}    ],    max_tokens=1024,    temperature=0.7) print(response.choices[0].message.content) # Optional: Enable context compression to reduce token usage# response = client.chat.completions.create(#     model="gemini-3.1-flash-tts-preview",#     messages=[{"role": "user", "content": "Hello!"}],#     extra_body={"compression": {"enabled": True, "model": "gpt-4.1-mini"}}# )

Supported Parameters

API docs

Common5 params

modelinputvoiceresponse_formatspeed

Extended2 params

instructionsstream_format

Cursor IDE Model IDs

Use these namespaced identifiers in Cursor IDE to avoid conflicts with built-in models.

gemini-3.1-flash-tts-preview

Compare with Other Models

See how this model compares to others from the same provider.

Gemini 2.5 Flash Preview 05-20 (thinking)

Gemini 2.5 Flash Preview (May 2025) is Google's high-performance general model built for advanced reasoning, coding, math, and science. It includes built-in “thinking” features to deliver more accurate, context-aware answers.

Context: 1.0M
Input: $0.075/M
Output: $1.75/M

Gemini 2.5 Flash Lite Preview 09-2025

Gemini 2.5 Flash-Lite is a lightweight, low-latency model focused on speed and cost efficiency. It generates tokens quickly and outperforms earlier Flash models on common benchmarks. “Thinking” (multi-pass reasoning) is off by default for maximum speed, but can be turned on through the Reasoning API when deeper reasoning is needed.

Context: 1.0M
Input: $0.05/M
Output: $0.20/M

Gemini 2.5 Flash Lite Preview 06-17

Gemini 2.5 Flash-Lite is a smaller, low-latency model focused on speed and cost efficiency. It delivers faster generation and better benchmark performance than earlier Flash models. Thinking mode is off by default for maximum speed, but developers can enable it when they want deeper reasoning at a higher cost.

Context: 1.0M
Input: $0.025/M
Output: $0.10/M

Gemini 2.5 Flash Preview (thinking)

Context: 1.0M
Input: $0.075/M
Output: $1.75/M