GLM-5.3

GLM-5.3 is Z.ai's August 2026 flagship, and the interesting part is how it was built: not a new pretrain, but extended post-training on the same base as GLM-5.2. The gains are concentrated where that kind of work pays off. Terminal-Bench 3.0 jumped from 4.6 to 28.3, DeepSWE v1.1 went from 46.2 to 66.9, and independent evaluation puts it at 95.4 on SWE-bench Verified. Z.ai also reports 62.5 on Humanity's Last Exam with tools and a notable cybersecurity capability that emerged rather than being targeted, with 54.4 on ExploitBench and 84.5 on CyberGym. Pricing is $1.40 per million input tokens and $4.40 output, with a 1M token context window and 128K max output. It launched API-first through the Z.ai API and Coding Plan, and the weights have since landed ungated on Hugging Face at zai-org/GLM-5.3, roughly 753 billion parameters. Read the license before you deploy. It is a custom GLM-5.3 License rather than the plain MIT that covered GLM-5.2: permissive for almost everyone, but any Model-as-a-Service operator whose group revenue tops $10 billion over 12 months must pass a Z.ai security review before commercial use. Treat every score here as vendor-reported except the independently run SWE-bench figure.