IndexTTS is an industrial-grade, controllable, and efficient zero-shot text-to-speech (TTS) system that supports Chinese and English and features advanced voice cloning functionality. Its sub-version IndexTTS2 is called a breakthrough autoregressive zero-shot TTS solution.
In terms of purpose, IndexTTS is designed to provide precise speech duration control, emotionally expressive speech generation, and to disentangle emotional expression from speaker identity. It is suitable for scenarios requiring high-quality, controllable speech synthesis and can be used without additional training.
Its main capabilities include: precise duration control, reproducing prosody by explicitly specifying the number of tokens and using autoregressive generation; emotional expression, reproducing various emotions such as anger, happiness, calmness, and fear in a zero-shot manner; timbre and emotion disentanglement, allowing independent control of speaker identity and emotional expression using different prompts; text-based emotion control, combined with Qwen3 integration, generating emotions through natural language descriptions. The system outperforms existing models in word error rate, speaker similarity, and emotional fidelity, and uses advanced GPT latent representations and soft instruction mechanisms to enhance speech stability.
In terms of usage, IndexTTS provides simple API integration that can be called with just a few lines of code, and the official documentation provides a Python API example. In addition, there are comprehensive guides and API references, open-source code and examples in the GitHub repository, and support provided by Discord and QQ groups.
Applicable scenarios include speech synthesis tasks that require zero-shot voice cloning in Chinese or English, precise control of speech duration, rich emotional expression, and independent control of timbre and emotion.
In terms of limitations, the materials currently do not provide the specific number of supported emotions, the speed control range, specific values for word error rate and speaker similarity, pricing or charging information, detailed usage restrictions on various platforms, or more technical details; this content is not yet available.
