GLM-5.2: New Open-Weight LLM Leads Benchmarks, Released Under MIT License

Jul 10, 2026

Chinese AI lab Z.ai has released GLM-5.2, a 753B-parameter Mixture-of-Experts model with 40 active parameters, under an MIT license. GLM-5.2 leads the Artificial Analysis Intelligence Index among open-weight models and ranks second on the Code Arena WebDev leaderboard, behind only Claude Fable 5. The model features a 1 million token context window and is available via OpenRouter at competitive pricing.

Why it matters: GLM-5.2 sets a new performance standard for open-weight text-only LLMs, rivaling proprietary models in coding and general intelligence benchmarks.

Full story at: Simon Willison's Weblog ↗