GLM 4.5 Air (free) vs GLM 5

GLM-4.5-Air is the lightweight version of our newest flagship model family, designed specifically for agent-focused applications. Like GLM-4.5, it uses a Mixture-of-Experts (MoE) architecture, but with a smaller parameter footprint. GLM-4.5-Air also supports hybrid inference modes, including a "thinking mode" for deeper reasoning and tool usage, and a "non-thinking mode" for real-time interactions.

GLM-5 is the flagship open-source foundation model from Z.ai, specifically designed for advanced systems engineering and handling long-term agent workflows. Tailored for skilled developers, it provides production-level performance on extensive programming tasks, matching up to the top proprietary models. Thanks to its sophisticated agent planning, robust backend reasoning, and iterative self-improvement, GLM-5 goes beyond simple code generation to enable comprehensive system creation and autonomous operation.