Coverage confirms Hy4's open-source release with 770B parameters and 49B active per token
Following·since 29 Aug 2026·Day 2·6 sources
Tencent Hy4 Preview: 770B MoE Open-Weight Model Benchmarked
The gist
Hy4 is among the largest open-weight models published, making a 770B-parameter MoE model available for download. Its coding benchmark results are competitive with several leading closed models, while graduate-level reasoning lags behind the top frontier tier.
The full picture
Tencent released Hy4 Preview on August 29, 2026, as an open-weight mixture-of-experts model with 770B total parameters and 49B active per token, supporting a 1M-token context window, up from Hy3's 256K. Weights are available on GitHub, Hugging Face, ModelScope, and GitCode/AtomGit. Benchmark analyses show large coding gains over Hy3: the DeepSWE score rose from 28.00 to 64.30 and SWE-bench Multilingual from 75.80 to 82.90. At 'High' thinking level, Hy4 scores 92.30 on GPQA Diamond and 55.40 on HLE; in text-only, no-tools mode, HLE drops to 43.4, behind Claude Opus 5 (54.9) and GPT 5.6 Sol (49.5). On enterprise benchmarks, Hy4 scores 78.6 on BankerToolBench, ahead of DeepSeek V4 Pro and Kimi K3 but behind GPT 5.6 Sol and Claude Opus 5. Tencent's deployment FAQ states that open-source release does not mean unrestricted commercial use and that preview status is not production approval.
How it developed
Tencent releases Hy4 Preview as an open-weight model with 770B parameters and 1M-token context window
Sources
Simon Willison
1 more source
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