World's First Autoregressive TTS with Precise Duration Control
Zero-Shot Voice Cloning

Transform Text intoEmotional Voice

IndexTTS2 delivers industrial-grade text-to-speech with revolutionary zero-shot voice cloning, precise duration control, and authentic emotional expression. IndexTTS2 is powered by advanced GPT technology for production-ready voice synthesis.

0-Shot
Voice Cloning
100%
Duration Control
Emotions

Live Interactive Demo

Try IndexTTS2 in your browser now

Industry-Leading Performance

IndexTTS2 benchmark results demonstrating superiority over existing zero-shot TTS models

↓ 15%
vs. Competitors

Word Error Rate

Superior intelligibility with significantly lower WER across multiple test datasets

92%+
Similarity

Speaker Similarity

Exceptional voice cloning fidelity maintaining timbre and vocal characteristics

88%+
Accuracy

Emotion Fidelity

Accurate emotional expression recognition matching intended sentiment

±10ms
Precision

Duration Control

Millisecond-level timing accuracy for perfect synchronization

* Benchmark results based on LibriSpeech, VCTK, and proprietary emotion datasets. Performance may vary based on use case.

Real-World Dubbing Showcase

Experience IndexTTS2's capabilities in professional video dubbing scenarios. IndexTTS2 delivers precise timing and emotional authenticity for production-ready content.

Let the Bullets Fly

Chinese Drama • Emotional Intensity

Emotion ControlPrecise Timing

Demonstrates dynamic emotional range from anger to subtle sarcasm with perfect lip-sync synchronization in Chinese dialogue.

Empresses in the Palace

Historical Drama • Nuanced Emotions

Subtle EmotionsCharacter Voice

Showcases delicate emotional nuances and refined voice characteristics essential for period drama dubbing.

Rick and Morty

Animation • English Dubbing

EnglishFast-Paced

Captures rapid-fire dialogue with character-specific voice quirks and comedic timing in English animation.

BanG Dream! It's MyGO!

Anime • Multi-Character

Anime StyleYouth Voice

Demonstrates energetic youth voices with anime-style expressiveness and character differentiation.

All videos demonstrate IndexTTS2's ability to maintain perfect timing synchronization while delivering authentic emotional expressions

Try It Yourself

Why Choose IndexTTS2

Revolutionary capabilities that set new standards in voice synthesis

Zero-Shot Voice Cloning

Clone any voice instantly without training. Just provide a reference audio and generate speech in that voice with perfect fidelity.

Precise Duration Control

Control speech timing with millisecond precision. Perfect for video dubbing, audiobooks, and synchronized multimedia content.

Decoupled Emotional Control

Industry-first emotion-identity decoupling - independently control voice timbre and emotional expression. Mix any speaker's voice with any emotion using text or audio prompts powered by Qwen3 fine-tuning.

GPT-Enhanced Stability

Integrated GPT latent representations ensure stable, high-quality speech generation. Industrial-grade architecture with GPU acceleration, FP16 support, and DeepSpeed optimization for production deployment.

Multi-Language Support

Supports multiple languages with mixed character input. Perfect for Chinese characters and Pinyin pronunciation control.

Open Source

MIT licensed and fully open-source. Access model weights, inference code, and complete documentation on GitHub.

Real-World Applications of IndexTTS2

Discover how IndexTTS2 zero-shot TTS technology transforms industries. IndexTTS2 provides AI-powered voice synthesis and emotional speech generation for professional applications.

Video Dubbing & Localization

Transform video content for global audiences with IndexTTS2's precise duration control and zero-shot voice cloning. IndexTTS2 creates authentic multilingual dubbing that matches original timing perfectly. Ideal for films, TV shows, YouTube content, and e-learning platforms.

Audiobook Production

Revolutionize audiobook creation with IndexTTS2 emotional voice synthesis. IndexTTS2 generates expressive narration with character-specific voices and emotional depth. Publishers produce high-quality audiobooks faster while maintaining natural storytelling quality.

AI Assistants & Chatbots

Build conversational AI with human-like emotional responses using IndexTTS2. IndexTTS2 enables virtual assistants, customer service bots, and smart home devices to communicate with appropriate emotional tone and personalized voice experiences.

Game Development

Generate dynamic game dialogue and character voices on-demand. IndexTTS2's zero-shot voice cloning creates unique character voices without expensive voice actor sessions. Perfect for indie developers, procedural narrative games, and large-scale RPGs requiring extensive voice content with emotional variety.

Accessibility Solutions

Empower accessibility tools with natural-sounding speech synthesis. IndexTTS2 provides screen readers, assistive communication devices, and text-to-speech apps with high-quality, emotionally expressive voices. Helps individuals with visual impairments or speech disabilities communicate more naturally and effectively.

Content Creation & Marketing

Scale content production with AI-generated voiceovers for marketing videos, podcasts, and social media. IndexTTS2 enables brands to create consistent voice identities across campaigns while maintaining flexibility for different emotional tones and regional adaptations without recording studio costs.

Technical Specifications

IndexTTS2 built on cutting-edge GPT architecture with industrial-grade performance optimization

Core Architecture

  • GPT-Based Model: Advanced transformer architecture for natural language understanding and speech generation
  • Zero-Shot Learning: No fine-tuning required - clone any voice from a single 3-10 second reference audio sample
  • Multi-Modal Input: Supports text prompts, audio references, and emotional control parameters simultaneously
  • Dual Generation Modes: Mode 1: Precise token count control for perfect timing. Mode 2: Free generation preserving natural prosody
  • Qwen3 Emotion Engine: Fine-tuned Qwen3 model enables natural language emotion guidance with soft instruction mechanism

Performance Optimization

  • GPU Acceleration: CUDA optimization for NVIDIA GPUs with FP16 mixed precision training support
  • DeepSpeed Integration: Distributed training and inference optimization for enterprise-scale deployment
  • Real-Time Generation: Low-latency inference capable of streaming audio generation for interactive applications

Audio Quality

  • High-Fidelity Output: 24kHz sampling rate with studio-quality audio generation and minimal artifacts
  • Natural Prosody: Advanced intonation modeling for realistic speech rhythm, stress patterns, and pitch contours
  • Duration Precision: Millisecond-level control over phoneme duration for perfect lip-sync and timing synchronization

Deployment Options

  • Cloud & On-Premise: Flexible deployment on AWS, GCP, Azure, or private infrastructure with containerization support
  • REST API: Production-ready HTTP API with comprehensive documentation and client libraries for multiple languages
  • Open Source License: MIT License with full access to model weights, training code, and inference pipeline implementation

Frequently Asked Questions

Everything you need to know about IndexTTS2 zero-shot text-to-speech technology

What is zero-shot voice cloning in IndexTTS2?

Zero-shot voice cloning means IndexTTS2 can replicate any voice from just a single short audio reference (3-10 seconds) without any training or fine-tuning. Unlike traditional TTS systems that require hours of training data, IndexTTS2 uses advanced GPT-based neural architecture to instantly capture voice characteristics including timbre, accent, speaking style, and prosody. IndexTTS2 makes it ideal for rapid prototyping, dynamic content creation, and applications requiring multiple unique voices.

How does IndexTTS2 emotional control work in speech synthesis?

IndexTTS2 features industry-first emotion-identity decoupling, offering unprecedented control flexibility through two complementary methods:

Text-Based Control: Use natural language prompts like "Generate this with a happy tone" or emotion keywords ("joyful", "melancholic", "excited"). Powered by fine-tuned Qwen3 with soft instruction mechanism for nuanced interpretation.
Audio-Based Control: Upload a short audio clip (3-10 seconds) capturing the desired emotion. IndexTTS2 extracts emotional characteristics and applies them while maintaining target speaker identity.
Decoupled Control: IndexTTS2 independently mixes voice timbre from Speaker A with emotional expression from Speaker B or text prompt. Create unlimited combinations without retraining.

The system modulates pitch variation, speaking rate, energy levels, and articulation style to produce authentic emotional expressions from subtle nuances to dramatic performances.

What makes IndexTTS2's duration control "precise"?

IndexTTS2 offers millisecond-level control over speech timing through explicit duration modeling at the phoneme level. Unlike standard TTS systems where speech timing is unpredictable, IndexTTS2 allows you to specify exact durations for each phoneme or word, ensuring perfect synchronization with video frames, animations, or music. IndexTTS2 is crucial for professional applications like video dubbing, lip-sync animation, audiovisual presentations, and any scenario requiring precise temporal alignment.

What are the system requirements for running IndexTTS2?

For optimal performance, IndexTTS2 recommends an NVIDIA GPU with at least 8GB VRAM (RTX 3070 or higher) for real-time inference. IndexTTS2 supports FP16 mixed precision for reduced memory usage and DeepSpeed optimization for large-scale deployment. CPU-only inference is possible but significantly slower. IndexTTS2 cloud deployment is supported on AWS, Google Cloud, and Azure with pre-configured Docker containers.

Is IndexTTS2 suitable for commercial use?

Yes, IndexTTS2 is released under the MIT License, making it fully suitable for commercial applications without licensing fees. You can integrate IndexTTS2 into commercial products, services, or applications, modify the source code, and distribute your implementations. IndexTTS2's open-source nature ensures transparency, customizability, and no vendor lock-in.

What languages does IndexTTS2 support?

IndexTTS2 primarily supports English and Chinese with robust handling of mixed-language input. IndexTTS2 can process Chinese characters with optional Pinyin annotations for precise pronunciation control. For English, IndexTTS2 handles various accents and speaking styles. While trained primarily on these languages, IndexTTS2's zero-shot capabilities may enable reasonable synthesis for other languages when provided with appropriate reference audio.

How does IndexTTS2 compare to other TTS solutions?

IndexTTS2 distinguishes itself through the combination of zero-shot voice cloning, precise duration control, and emotional expression in a single unified model. While commercial services like Google Cloud TTS or Amazon Polly offer high quality, they lack voice cloning and precise timing control. IndexTTS2 bridges the gap by offering enterprise-grade quality with the flexibility of zero-shot synthesis, making IndexTTS2 ideal for applications requiring multiple voices, emotional variety, and precise synchronization.

How do I get started with IndexTTS2?

Getting started with IndexTTS2 is straightforward. Try our live interactive demo above to experience IndexTTS2 zero-shot voice cloning firsthand. IndexTTS2 provides comprehensive documentation including installation guides, API references, code examples, and implementation best practices. You can deploy IndexTTS2 on your infrastructure or cloud platform of choice.

Ready to Transform Your Voice Experience?

Join thousands of developers and creators using IndexTTS2 zero-shot voice cloning to bring their projects to life with IndexTTS2 AI-powered voice synthesis