Hy-MT1.5-1.8B-1.25bit

<p align="center"> <picture> <source media="(prefers-color-scheme: dark)" srcset="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/logos/angelslim_logo_light.png?raw=true"> <img alt="AngelSlim" src="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/logos/angelslim_logo.png?raw=true" width=55%> </picture> </p> <h3 align="center"> Dedicated to building a more intuitive, comprehensive, and efficient LLMs compression toolkit. </h3> <p align="center"> 📱 <a href="https://huggingface.co/AngelSlim/Hy-MT1.5-1.8B-2bit-GGUF/resolve/main/Hy-MT-demo.apk?download=true">Android Demo</a>&nbsp;&nbsp; | &nbsp;&nbsp; 📣 <a href="https://huggingface.co/AngelSlim/Hy-MT1.5-1.8B-1.25bit-GGUF">GGUF</a>&nbsp;&nbsp; | &nbsp;&nbsp; ✒️ <a href="https://arxiv.org/abs/2601.07892">Sherry Paper (ACL 2026)</a>&nbsp;&nbsp; | &nbsp;&nbsp; 📖 <a href="https://angelslim.readthedocs.io/">Documentation</a>&nbsp;&nbsp; | &nbsp;&nbsp; 🤗 <a href="https://huggingface.co/AngelSlim">AngelSlim</a>&nbsp;&nbsp; | &nbsp;&nbsp; 💬 <a href="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/angel_slim_wechat.png?raw=true">WeChat</a> <br> </p> <p align="center"> <img src="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/HYMT1.5/model_scores.png?raw=true" alt="model_scores" width="80%"> <br> <em>Hy-MT1.5-1.8B translation quality scores. Source: <a href="https://arxiv.org/abs/2512.24092">HY-MT1.5 Technical Report</a></em> </p>

📣 Latest News

• [26/04/29] We have released Hy-MT1.5-1.8B-2bit (574MB) and Hy-MT1.5-1.8B-1.25bit (440MB), on-device translation models supporting 33 languages, with both weights and GGUF formats available. We have also made an Android Demo for you to try out. We invite you to give it a spin! 🔥🔥🔥
• [26/02/09] We have released HY-1.8B-2Bit, 2-bit on-device large language model.
• [26/01/13] We have released v0.3. We support the training and deployment of Eagle3 for all-scale LLMs/VLMs/Audio models. And we released Sherry, the hardware-efficient 1.25-bit quantization algorithm [Paper] | [Code]

For more detailed information, please refer to [AngelSlim] and [HY-MT]

🌟 Hy-MT1.5-1.8B-1.25bit Key Features

• World-Class Translation Quality Hy-MT1.5-1.8B-1.25bit is built upon the Hy-MT1.5-1.8B foundation model, a specialized translation model developed by Tencent Hunyuan Team through a holistic multi-stage training pipeline integrating MT-oriented pre-training, supervised fine-tuning, on-policy distillation, and reinforcement learning. The base model natively supports 33 languages, 5 dialects/minority languages, and 1,056 translation directions. With only 1.8B parameters, it comprehensively outperforms much larger open-source models (e.g., Tower-Plus-72B, Qwen3-32B) and mainstream commercial translation APIs (e.g., Microsoft Translator, Doubao Translator). For full details, please refer to the HY-MT1.5 Technical Report.

• Sherry: Extreme 1.25-bit Quantization This model employs Sherry (accepted at ACL 2026), a hardware-efficient ternary quantization framework. Sherry introduces a 3:4 fine-grained sparsity strategy: for every 4 model weights, the 3 most important are stored in 1-bit ({-1, +1}), while the remaining 1 is zeroed out. This packs 4 weights into just 5 bits, achieving an effective 1.25-bit width with power-of-two alignment, compressing the original 3.3GB FP16 model to just 440MB, with minimal accuracy loss.

<p align="center"> <img src="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/HYMT1.5/Sherry.png?raw=true" alt="Sherry" width="80%"> <br> <em>Sherry fine-grained sparsity: for every 4 weights, the 3 most important are stored in 1-bit, and the remaining 1 is zeroed out.</em> </p>

• On-Device Deployment for the Most Phones Paired with our custom STQ kernel designed specifically for mobile CPUs, the 1.25-bit model achieves perfect SIMD instruction set alignment. This means even ordinary phones with limited memory can run high-quality offline translation smoothly. No internet connection required, and your data never leaves the device.

📈 Translation Benchmarks

Performance comparison of different model sizes on the Flores-200 Chinese-Foreign mutual translation benchmark:

<p align="center"> <img src="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/HYMT1.5/flores_model_size.png?raw=true" alt="flores_model_size" width="80%"> <br> <em>Performance of different model sizes on the Flores-200 Chinese-Foreign mutual translation benchmark.</em> </p>

⚡ Speed Demo

FP16 (8x speed) vs. 1.25-bit speed comparison. Demo device: Snapdragon 888, 8GB RAM:

<p align="center"> <img src="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/HYMT1.5/fp16vs1.25bit.gif?raw=true" alt="fp16_vs_1.25bit" width="60%"> <br> <em> Demo device: Snapdragon 888, 8GB RAM.</em> </p>

📱 Demo

We provide a ready-to-use Android demo for offline translation. The demo features a background word extraction mode that works across any app on your phone — browse emails, webpages, or chat messages and get instant translations without switching apps. No network required, no data collection, one-time download for permanent use.

Download Demo:

https://huggingface.co/AngelSlim/Hy-MT1.5-1.8B-1.25bit-GGUF/resolve/main/Hy-MT-demo.apk

Translation Demo

<p align="center"> <img src="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/HYMT1.5/app_demo.gif?raw=true" alt="app_demo" width="40%"> <br> <em>Demo device: Snapdragon 865, 8GB RAM.</em> </p>

Background Word Extraction Mode

<p align="center"> <img src="https://github.com/Tencent/AngelSlim/blob/main/docs/source/assets/HYMT1.5/demo2.gif?raw=true" alt="demo2" width="40%"> <br> <em>Demo device: Snapdragon 7+ Gen 2, 16GB RAM.</em> </p>

📥 Download Links

• 1.25-bit model weights: https://huggingface.co/AngelSlim/Hy-MT1.5-1.8B-1.25bit
• 1.25-bit model GGUF: https://huggingface.co/AngelSlim/Hy-MT1.5-1.8B-1.25bit-GGUF
• 2-bit model weights: https://huggingface.co/AngelSlim/Hy-MT1.5-1.8B-2bit
• 2-bit model GGUF: https://huggingface.co/AngelSlim/Hy-MT1.5-1.8B-2bit-GGUF
• Demo: https://huggingface.co/AngelSlim/Hy-MT1.5-1.8B-1.25bit-GGUF/resolve/main/Hy-MT-demo.apk

📄 Technical Reports

• HY-MT1.5 Technical Report: https://arxiv.org/abs/2512.24092
• Sherry Paper (ACL 2026): https://arxiv.org/abs/2601.07892
• AngelSlim Technical Report: https://arxiv.org/abs/2602.21233

📝 License

The code for this project is open-sourced under the License for AngelSlim.

🔗 Citation

@misc{huang2026sherry,
      title={Sherry: Hardware-Efficient 1.25-Bit Ternary Quantization via Fine-grained Sparsification}, 
      author={Hong Huang and Decheng Wu and Qiangqiang Hu and Guanghua Yu and Jinhai Yang and Jianchen Zhu and Xue Liu and Dapeng Wu},
      year={2026},
      eprint={2601.07892},
      archivePrefix={arXiv},
      primaryClass={cs.LG},
      url={https://arxiv.org/abs/2601.07892}, 
}

@article{angelslim2026,
  title={AngelSlim: A more accessible, comprehensive, and efficient toolkit for large model compression},
  author={Hunyuan AI Infra Team},
  journal={arXiv preprint arXiv:2602.21233},
  year={2026}
}

@misc{zheng2025hymt,
      title={HY-MT1.5 Technical Report}, 
      author={Mao Zheng and Zheng Li and Tao Chen and Mingyang Song and Di Wang},
      year={2025},
      eprint={2512.24092},
      archivePrefix={arXiv},
      primaryClass={cs.CL},
      url={https://arxiv.org/abs/2512.24092}, 
}

💬 Technical Discussion

• AngelSlim is continuously iterating and new features will be released soon. If you have any questions or suggestions, please open an issue on GitHub Issues or join our WeChat discussion group.