Tencent Hunyuan Releases Open-Source Hy4 Preview Model

The report said that in a blind test involving 163 internal experts and 203 engineering tasks, Hy4 preview scored 2.99 out of 4, slightly outperforming GLM 5.3 (2.92) and Kimi K3 (2.94). The model is positioned as "built for productivity," co-designed with Tencent's products such as CodeBuddy and WorkBuddy, and developed with high-quality data from Tencent experts in software engineering, gaming, finance, and security.

In software engineering scenarios, the model enhances long-duration development tasks including understanding, planning, debugging, and verification, while improving visual aesthetics and interaction quality in front-end development. In office analysis, it improves complex office environment understanding and financial analysis, focusing on data analysis and cross-file collaboration to deliver documents, spreadsheets, and presentations. For game development, it can generate playable prototypes from a single requirement and use game engines through multi-turn interactions. In scientific research, the model strengthens understanding, reasoning, and problem-solving in complex scientific topics, with advances in AI R&D, molecular dynamics simulations, condensed matter physics, and fundamental mathematics.

The report also highlighted that Hy4 preview played an active role in its own R&D process, participating in automatic optimization of training methods, data strategies, evaluation systems, and underlying operators. The model proposes solutions, runs experiments, and iterates based on results, forming a preliminary recursive self-improvement loop. It also analyzed inference system bottlenecks and performed optimizations in operator fusion and communication, improving end-to-end throughput by 31.8% over the baseline across different context lengths and concurrency levels.

Hy4 preview has been open-sourced and is simultaneously available in Tencent products including WorkBuddy, CodeBuddy (domestic and international versions), Yuanbao, and ima. Users can also access it via Tencent Cloud Tokenhub and OpenRouter API. The pricing remains accessible: 6 yuan per million input tokens, 18 yuan per million output tokens, and 0.3 yuan per million tokens for cache hits. WorkBuddy and CodeBuddy are offering a two-week free trial to collect user feedback.

Since rebuilding its infrastructure in February, Hunyuan has iterated a major version every two months on average. Through a preview-first approach followed by formal releases, Tencent integrates real-world feedback into the development cycle. The next version of Hy4 is expected to launch soon, according to the report.