# Tencent open-sources Hy4 preview with 770B parameters and a 1M-token context > Source: > Published: 2026-08-28 13:32:49+00:00 Tencent Hunyuan [released and open-sourced Hy4 preview](https://hy.tencent.ai/research/hy4-preview) on Aug. 28. The next-generation large language model has 770 billion total parameters, 49 billion activated parameters and a context window exceeding 1 million tokens. It is available through the Chinese and international versions of WorkBuddy and CodeBuddy, as well as Yuanbao and ima, with API access offered through Tencent Cloud TokenHub and OpenRouter. Hy4 preview is designed for productivity tasks including coding, office work, data analysis, game development and scientific research. WorkBuddy and CodeBuddy will offer users free access for a limited two-week period, while the API is priced at $0.834 per million input tokens and $2.501 per million output tokens. In an internal blind evaluation involving 163 experts and 203 engineering tasks, Hy4 preview achieved an average score of 2.99 out of 4, compared with 2.92 for GLM 5.3 and 2.94 for Kimi K3. Tencent also said the model helped optimize parts of its own training and inference systems, increasing end-to-end throughput by 31.8% against a baseline. [TechNode reporting]