IndexTTS2

An Industrial-Level Controllable and Efficient Zero-Shot Text-to-Speech System

简体中文 | English | 日本語 | Español | العربية

IndexTTS is a zero-shot text-to-speech system that clones a voice from a single
reference audio clip. The latest release, IndexTTS-2.5, supports Chinese,
English, Japanese, Spanish and Arabic, with fine-grained emotion control,
speaking speed control, pronunciation control (Pinyin / CMU phonemes /
Japanese Kana), and faster inference than IndexTTS-2.

🗂️ Model Zoo

| Model | Demos | Paper | ModelScope | HuggingFace |
| IndexTTS-2.5 |    |  |  |  |
| IndexTTS-2 |  |  |  |  |
| IndexTTS-1.5 |  |  |  |  |
| IndexTTS |  |  |  |  |

📣 News

- 2026/08/10 🔥 We release IndexTTS-2.5
  - Now supports Chinese, English, Japanese, Spanish and Arabic, with faster inference than IndexTTS-2, while keeping the cross-lingual and timbre-emotion disentanglement capabilities.
  - Improved controllability of Chinese Pinyin, English CMU phonemes and Japanese Kana.
  - Speaking speed control via duration_factor (0.5x–2.0x duration).
  - Production deployment supported via vLLM.
- 2025/09/08 🔥 We release IndexTTS-2
  - The first autoregressive TTS model with precise synthesis duration control, supporting both controllable and uncontrollable modes. This functionality is not yet enabled in this release.
  - Highly expressive emotional speech synthesis, with emotion control through multiple input modalities.
- 2025/05/14 🔥 We release IndexTTS-1.5, significantly improving the model's stability and its performance in English.
- 2025/03/25 🔥 We release IndexTTS-1.0 with model weights and inference code.
- 2025/02/12 🎉 We submitted our paper to arXiv, and released our demos and test sets.

🎬 Demos

IndexTTS-2.5: The Future of Voice, Now Generating

IndexTTS-2: The Future of Voice, Now Generating

🚀 Getting Started

1. Prerequisites

Make sure you have git installed, then download
this repository:

bash
git clone https://github.com/index-tts/index-tts.git && cd index-tts

Example audio files are downloaded on demand from HuggingFace/ModelScope the
first time the WebUI starts, so Git LFS is no longer required.

2. Install Dependencies

We use uv to manage
the project's dependency environment. It is required for a reliable
installation:

bash
pip install -U uv  # or see the link above for other install methods

bash
uv sync --all-extras

This automatically creates a .venv project directory and installs the correct
versions of Python and all required dependencies.

If the download is slow, use a local mirror, e.g. one of these mirrors in China:

bash
uv sync --all-extras --default-index "https://mirrors.aliyun.com/pypi/simple"

uv sync --all-extras --default-index "https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple"

> [!TIP]
> Available Extra Features:
>
> - --all-extras: Automatically adds *every* extra feature listed below. You can
>   remove this flag if you want to customize your installation choices.
> - --extra webui: Adds WebUI support (recommended).
> - --extra deepspeed: Adds DeepSpeed support (may speed up inference on some
>   systems).

> [!IMPORTANT]
> Windows: DeepSpeed may be difficult to install. You can skip it by removing
> the

……（后略，见原文）