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GLM-5.2 is probably the most powerful text-only open weights LLM

Simon Willison · Jun 17, 2026 · Product Launches

GLM-5.2 is now the leading open weights LLM on Artificial Analysis's Intelligence Index, released under MIT license.

“GLM-5.2 is the leading open weights model on the Intelligence Index v4.1.”

Chinese lab Z.ai released GLM-5.2, a 753B-parameter (40B active) MoE text-only model with a 1M token context window, under an MIT open weights license. It tops the Artificial Analysis Intelligence Index for open weights models and ranks 2nd on Code Arena WebDev behind Claude Fable 5, though it is notably token-hungry. This matters as a strong signal that open weights models continue closing the gap with frontier proprietary models at a fraction of the cost.

open-weights GLM-5.2 Z.ai benchmarks coding-models

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