Dia2 is a streaming dialogue TTS model designed specifically to produce speech in real time. Traditional TTS models require the entire text to be processed before generating output audio. In contrast, Dia2 can start speaking from the very first words, making it exceptionally fast and interactive.
Key aspects of Dia2 include:
- Streaming generation without needing full text
- Audio conditioning, allowing it to mimic conversational style
- Real-time interaction, ideal for voicebots and assistants
- Open-weight availability, with 1B and 2B parameter sizes
- Up to 2 minutes of continuous generation in English
Core Features of Dia2
1. Streaming Dialogue TTS
Dia2’s design allows it to generate speech as input text is received. This enhances natural flow during human-AI interactions and reduces audio delay. It is particularly useful for:
- Real-time assistants
- Interactive chatbots
- Live translation tools
- Voice-controlled applications
2. Audio Conditioning for Realistic Voice Interaction
Dia2 shines when conditioned on prefix audio, which allows it to adopt conversational tone and match voice context. By feeding in previous conversational audio snippets, the model produces more coherent, context-aware, and natural-sounding dialogue.
This makes Dia2 an excellent choice for:
- Customer support agents
- AI companions
- Multi-speaker dialogue systems
3. Multi-Speaker Support
Using speaker tags such as [S1] and [S2], Dia2 can simulate multi-party conversation and switch between speakers automatically. This is essential for dialogue systems, speech actors, and complex chat simulations.
4. Efficient GPU Utilization
Dia2 integrates:
- CUDA graph optimization
- Support for CUDA 12.8+
- bfloat16 precision
- Automatic device selection
This results in fast generation speeds even on mid-range GPUs.
5. Open-Source Availability
Nari Labs provides:
- Weights for Dia2-1B and Dia2-2B
- Inference scripts
- Gradio demo interface
- Example prefix audio files
Developers can explore, modify, or extend the model freely under the Apache 2.0 license.
Installation and Quickstart Guide
Dia2 requires uv, CUDA 12.8+ drivers, and Python dependencies provided in the repository.
Step 1: Install dependencies
uv sync
Step 2: Prepare input
Edit input.txt using [S1] and [S2] tags.
Step 3: Generate audio
uv run -m dia2.cli \
–hf nari-labs/Dia2-2B \
–input input.txt \
–cfg 6.0 –temperature 0.8 \
–cuda-graph –verbose \
output.wav
The command downloads weights during the first run and generates audio instantly afterward.
Conditional Audio Generation
For stable, natural-sounding output, conditional generation is recommended.
uv run -m dia2.cli \
–hf nari-labs/Dia2-2B \
–input input.txt \
–prefix-speaker-1 example_prefix1.wav \
–prefix-speaker-2 example_prefix2.wav \
–cuda-graph –verbose \
output_conditioned.wav
Dia2 uses Whisper internally to transcribe prefix audio, which helps the model align its responses with the dialogue context.
Gradio Web Interface for Easy Use
Launching the Gradio app is simple:
uv run gradio_app.py
This provides a web-based interface for audio generation, making experimentation more intuitive for beginners.
Programmatic Usage for Developers
Developers can directly integrate the model in Python:
from dia2 import Dia2, GenerationConfig, SamplingConfig
dia = Dia2.from_repo(“nari-labs/Dia2-2B”, device=”cuda”, dtype=”bfloat16″)
config = GenerationConfig(
cfg_scale=2.0,
audio=SamplingConfig(temperature=0.8, top_k=50),
use_cuda_graph=True,
)
result = dia.generate(
“[S1] Hello Dia2!”,
config=config,
output_wav=”hello.wav”,
verbose=True
)
The output includes waveform tensors, audio tokens, and timestamps.
Use Cases and Applications
1. Real-Time Voice Assistants
Dia2 can respond instantly, making it ideal for smart assistants requiring fluid dialogue.
2. Speech-to-Speech Systems
When paired with ASR models such as Whisper, Dia2 becomes the backbone of a complete speech-to-speech pipeline.
3. Conversational AI Agents
Its multi-speaker and prefix-conditioning abilities enable realistic multi-turn dialogues.
4. Customer Support Automation
Businesses can use Dia2 to create voice-based support systems with natural interaction quality.
5. Research and Prototyping
As an open-weight model, Dia2 is highly suitable for academic and industrial research.
Ethical Use and Restrictions
Nari Labs prohibits the following:
- Generating audio resembling real individuals
- Creating deceptive or harmful content
- Any illegal usage
Dia2 is intended strictly for ethical and research-oriented applications.
Conclusion
Dia2 represents a major step forward in streaming text-to-speech generation. Its ability to start speaking immediately, support multi-speaker dialogue, and condition outputs based on audio prefixes makes it one of the most advanced conversational TTS models available today. With 1B and 2B open-weight variants, real-time inference support, and easy integration, Dia2 opens new possibilities for interactive AI systems, speech-driven applications, and research in natural voice generation. As Nari Labs continues to expand the ecosystem with upcoming JAX implementations and Rust-based engines, Dia2 is set to play a crucial role in shaping the future of real-time conversational AI.