ZZ.ai

GLM-5.3 is Z.ai's post-trained coding and agent model built on the same base model as GLM-5.2. Z.ai positions it for complex coding, long-horizon tasks, and cybersecurity evaluation, with mandatory thinking, low, high, and max reasoning effort, and availability through GLM Coding Plan and ZCode at launch.

GLM-5.3-Flash is Z.ai's first natively multimodal GLM-5 model: a 320B-parameter mixture-of-experts checkpoint with 18B active parameters, hybrid sparse and linear attention, and MIT-licensed weights. Z.ai documents API access as glm-5.3-flash, Coding Plan and ZCode availability, and Hugging Face weights for SGLang, vLLM, and TokenSpeed.