Tencent Releases Hy4 Preview, an Open-Source Model Rivaling Top AI

Tencent today released its new open-source AI model, Hy4 preview, with 770B total parameters, 49B active parameters, and a 1M context length. The model sees major upgrades in size, context, and data, and Tencent says its intelligence is now among the top tier of open-source models.

Hy4 preview shines in real-world tasks like software engineering, office work, game development, and scientific research. For example, it can better understand and debug long coding tasks, improve front-end design quality, and in office settings, it optimizes data analysis and cross-file collaboration, handling everything from info processing to creating documents and slides. In game dev, it can turn a single sentence into a playable prototype and supports multi-turn refinement.

In blind tests, 163 internal experts scored Hy4 preview at 2.99/4.00 across 203 engineering tasks, slightly beating GLM-5.3 (2.92) and Kimi K3 (2.94). Teamed with Hyra, the model made a breakthrough on the classic 3D Blaschke-Lebesgue problem, pushing the volume lower bound from 0.380799 to 0.41104, leaving just a 2% gap to final proof.

As an early version, Hy4 preview is now open-sourced and available on Tencent Cloud TokenHub and OpenRouter, plus products like WorkBuddy, CodeBuddy, Yuanbao, and ima. Tencent says it will keep iterating quickly to improve the final Hy4 release.