GLM-5.3
Overview
GLM-5.3 is a text foundation model released by Z.AI on August 14, 2026 for complex coding, long-horizon agent tasks, and cybersecurity work. It uses the same base model as GLM-5.2; Z.AI attributes the update's gains to scaled post-training across more environments, more diverse tasks, and longer trajectories.
GLM-5.3
Eligibility: This offer applies to GLM-5.3 requests made through the B.AI API and B.AI web app.
For a limited time, eligible requests are billed at 90% of the standard reference price: Input 1.26, Cache Write 1.26, Cache Read 0.252, and Output 3.96 Credits/Token.
This page continues to show standard reference prices. Offer end time, eligibility, actual settlement prices, and final billing are subject to the platform display.
Key Features
- Scaled Post-Training: Retains the GLM-5.2 base model while expanding reinforcement-learning environments, task diversity, and training compute for long-horizon professional workflows.
- Configurable Always-On Reasoning: Supports
low,high, andmaxreasoning effort, withmaxas the default. Native GLM-5.3 requests require thinking to remain enabled. - Coding and Agent Performance: Z.AI reports 28.3 on Terminal-Bench 3.0, 66.9 on DeepSWE v1.1, 78.1 on FrontierSWE, and 48.2 on AutomationBench v1.0.6.
- Cybersecurity Evaluation: Z.AI reports 84.5 on CyberGym, 54.4 on ExploitBench, and 105/130 completed ExploitGym tasks under normalized two-hour/six-hour budgets.
- 1M-Token Coding Workflows: The GLM Coding Plan supports a 1M-token context. Claude Code users enable it with the
glm-5.3[1m]model name and a 1,000,000-token auto-compaction window.
Best Use Cases
- Complex Software Engineering: Repository-scale implementation, debugging, performance optimization, and test-fix-verify loops that require sustained work across many files and tools.
- Long-Horizon Coding Agents: ZCode, Claude Code, Codex, OpenCode, Cline, and other configurable agents that can use Z.AI's Anthropic-compatible or OpenAI-compatible Coding Plan endpoints.
- Authorized Security Research: Vulnerability discovery, validation, and exploit-chain analysis in systems the operator is permitted to test.
- Tool-Driven Professional Workflows: Multi-step engineering and research tasks with executable environments, objective verification, and iterative feedback.
Capabilities and Limitations
| Capability | Description |
|---|---|
| Reasoning | Thinking is always enabled. reasoning_effort supports low, high, and max; the default is max, which Z.AI recommends for coding tasks. |
| Creative Writing | General text generation is available. |
| Coding | Z.AI reports Terminal-Bench 2.1: 88.2, Terminal-Bench 3.0: 28.3, DeepSWE v1.1: 66.9, NL2Repo: 58.0, FrontierSWE: 78.1, and SWE-Marathon v1.1: 42.5. |
| Multimodal | Text input and text output. |
| Response Speed | Not published as a guaranteed API rate. |
| Context Window | Up to 1M tokens in GLM Coding Plan workflows. Claude Code requires the glm-5.3[1m] suffix to enable the 1M-token mode. |
| Max Output | Not published as a general API limit. |
| Tool Use | Designed and evaluated in tool-using coding-agent harnesses; available to Coding Plan users through ZCode and configurable Anthropic-compatible or OpenAI-compatible agents. |
| Multilingual | Natural-language prompting is supported. |
Known Limitations
- Native GLM-5.3 API requests do not support
thinking.type: "disabled"; applications must enable thinking and can choosereasoning_effort: "low"for lighter reasoning. The Coding Plan compatibility layer may automatically map disabled thinking tolow. - The model is text-only; image, audio, and video inputs are not advertised for GLM-5.3.
Credits Usage
| Model | Input (Credits/Token) | Cache Write (Credits/Token) | Cache Read (Credits/Token) | Output (Credits/Token) | Web Search (Credits/Use) | Billing Notes |
|---|---|---|---|---|---|---|
| GLM-5.3 | 1.40 | 1.40 | 0.28 | 4.40 | - | - |
Prices shown in the documentation are B.AI standard reference prices for base billing purposes. B.AI may provide lower actual usage costs through top-up bonuses and account benefits. Specific prices, bonus Credits, and account benefits are subject to the platform display and final billing records.