Tencent has thrown open the doors on its latest Hunyuan flagship. Hy4 preview, released Thursday, is now open source with 770 billion total parameters, a 49 billion-parameter active set, and a context window past 1 million tokens.
Tencent is positioning Hy4 for productivity work: coding, office tasks, data analysis, game development, and scientific research. It is available through the company’s WorkBuddy and CodeBuddy apps, which offer free access for a limited two-week period, plus Yuanbao and ima. Developers can reach it through Tencent Cloud TokenHub and OpenRouter, with API pricing at $0.834 per million input tokens and $2.501 per million output tokens.
Internally, Tencent put Hy4 in front of 163 experts working 203 engineering tasks and logged an average score of 2.99 out of 4, a hair ahead of the 2.92 and 2.94 posted by GLM 5.3 and Kimi K3. The company adds that the model, applied to its own infrastructure, pushed end-to-end throughput up 31.8%.
The release deepens competition in open-weight AI, where Chinese labs increasingly set the pace. Startups that build on open models gain a cheaper option with enterprise-grade context length, and rival labs face fresh pressure to match its quality claims.
