--- title: "GLM-5.2 is probably the most powerful text-only open weights LLM" url: https://daily.dev/posts/glm-5-2-is-probably-the-most-powerful-text-only-open-weights-llm-gwrkpxu3l source_url: https://simonwillison.net/2026/Jun/17/glm-52 type: article source: "Simon Willison" published: 2026-06-18T00:10:44.717Z updated: 2026-06-18T09:12:40.404Z tags: ["llm", "mixture-of-experts"] reading_time: 3 upvotes: 1 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # GLM-5.2 is probably the most powerful text-only open weights LLM **[Simon Willison](https://daily.dev/sources/simonwillison)** · 3 min read · 1 upvotes · 0 comments ## Summary Z.ai released GLM-5.2, a 753B parameter Mixture of Experts model with 40 active parameters and a 1 million token context window, under an MIT license. It tops the Artificial Analysis Intelligence Index for open weights models and ranks 2nd on the Code Arena WebDev leaderboard despite being text-only (no vision input). Pricing via OpenRouter is $1.40/$4.40 per million tokens for input/output, significantly cheaper than GPT-5.5 or Claude Opus. The model is notably token-hungry, using 43k output tokens per benchmark task. Simon Willison tested it with SVG generation prompts, finding the pelican result impressive but the opossum a step down from GLM-5.1. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#llm](https://daily.dev/tags/llm), [#mixture-of-experts](https://daily.dev/tags/mixture-of-experts) [View this post on daily.dev](https://daily.dev/posts/glm-5-2-is-probably-the-most-powerful-text-only-open-weights-llm-gwrkpxu3l)