Z.ai Releases GLM-5.3 With 50% Code Benchmark Gain; Weights to Follow in Two Weeks

Z.ai, the developer behind the GLM model family, released GLM-5.3 on August 14, marking its latest model update. The new model shares the same base model as GLM-5.2, with performance gains attributed to an expanded post-training phase, according to the company. In its own Z.ai Code Bench coding benchmark, GLM-5.3 beat GLM-5.2 by 50%. On public evaluations that include Terminal Bench 3.0 and Agents' Last Exam, GLM-5.3 reached the leading tier among open-weight models. Cybersecurity results improved as well. The model scored 84.5% on CyberGym's vulnerability discovery benchmark and posted large gains on exploit-chain tests like ExploitBench and ExploitGym, compared with the earlier release. Z.ai said weights will open two weeks after the launch, with security assessment and hardening still in progress. On the API side, the model drops the option to disable thinking mode, replacing it with three reasoning intensity settings: low, high, and max.