Hy4 preview is Tencent's open-source flagship-class large language model, released under the Apache 2.0 license and distributed through Tencent's Hugging Face, ModelScope, cnb.cool, and GitCode mirrors alongside a public GitHub repository. Tencent describes it as a next-generation system with 770B total parameters and 49B active parameters, signaling a Mixture-of-Experts style sparse design in which a relatively small active slice is routed for each inference while a much larger pool of experts provides capacity. The model was expanded substantially in scale, training-data volume, and post-training refinement, with Tencent positioning the resulting leap in overall intelligence as placing Hy4 preview among the top tier of open-source models rather than as a specialized narrow release.
Hy4 preview is purpose-built for real-world productivity, with Tencent highlighting standout performance across coding, office work, and scientific research rather than purely academic benchmarks. The model supports long-form, document-heavy workflows through a context window exceeding one million tokens, making it suitable for repository-scale code reasoning, long-report drafting, and literature-style research tasks. Tencent co-designed the model with its own productivity products, including CodeBuddy and WorkBuddy, optimizing the user experience around practical engineering and office scenarios, and the weights are openly available for self-hosting, fine-tuning, and integration into bespoke pipelines by teams that need a large, openly licensed base model.