Z Ai: GLM 5.3
GLM-5.3 is a large-scale reasoning model from Z.ai, built for complex software engineering and long-horizon agent tasks. It supports text input and output with a 1M-token context window, and improves on GLM-5.2 in coding and in the balance between performance and token efficiency. Reasoning is always on and cannot be disabled. Reasoning efforts `low`, `high`, and `max` are supported; `max` is the default.
Specifications
| Attribute | Value |
|---|---|
| Lab | Z Ai |
| Tags | Intelligent Coding Reasoning Agentic Long Context |
| Release Date | 2026-08 |
| Context Window | 1,048,576 tokens |
| Input Price / 1M | $1.40 |
| Output Price / 1M | $4.40 |
| Input Modalities | Text |
| Output Modalities | Text |
Strengths
- Million-token context window for very long tasks
- Tool-use support for agentic workflows
- Structured output support for reliable application integration
Weaknesses
- Newer listing with limited independent benchmark coverage
- Text-only inputs limit multimodal application coverage
Best For
- Agentic workflows and tool-using applications
- Long-context document and codebase processing
In Depth: GLM 5.3
Summary
GLM 5.3 is an AI model from Z Ai.
Released 2026-08. It supports Text input and produces Text output, with a context window of 1,048,576 tokens. Input pricing is $1.40 per 1M tokens and output is $4.40 per 1M tokens on OpenRouter.