GLM 5.3 Flash API

Built for reasoning, coding, and long-context agent tasks, improving over GLM-5.1 in context length, tool use, and complex multi-step workflows. Compared with Chinese flagship peers such as Qwen, DeepSeek, and Kimi, it fits enterprise automation, project-level code analysis, and knowledge work in Chinese.

A flagship workhorse for complex software engineering and long-horizon agent tasks. It uses the same base model as GLM-5.2, with improvements driven by post-training, delivering a 50% gain on Z.ai Code Bench alongside stronger terminal-operation and vulnerability-discovery capabilities. It offers a 1M-token context window, up to 128K output, always-on reasoning with low, high, and max effort levels, function calling, and structured outputs. It currently accepts text only and is not intended for tasks requiring visual understanding.

Built for image generation and editing, with a stronger focus than earlier GLM vision capabilities on Chinese prompts, image-text understanding, and controllable generation. Compared with GPT Image, Gemini image models, and Qwen Image, it fits Chinese marketing assets, explanatory visuals, and iterative visual edits.