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GLM-5.3

Z.aiOpen WeightsPending Human Review

GLM-5.3 advances coding, long-horizon engineering, and vulnerability-analysis capabilities through post-training on the GLM-5.2 base model. The model remains text-based and supports a million-token context, selectable reasoning effort, and persistent thinking history. Z.ai initially announced hosted availability before releasing downloadable weights. Those weights use the custom GLM-5.3 License rather than the MIT license of earlier GLM-5 models. It is distinct from GLM-5.3-Flash, which introduces a new native multimodal architecture.

2026-08-14
744B total, 40B activated
Mixture of Experts (MoE) with sparse attention and IndexShare
GLM-5.3 License

Specifications

Parameters
744B total, 40B activated
Architecture
Mixture of Experts (MoE) with sparse attention and IndexShare
License
GLM-5.3 License
Context Window
1,048,576 tokens
Type
text
Modalities
text

Benchmark Scores

Advanced Specifications

Model Family
GLM
API Access
Available
Chat Interface
Not Available

Capabilities & Limitations

Capabilities
reasoningcode generationtool uselong-context understanding
Known Limitations
Self-hosting the full MoE checkpoint requires substantial weight memory.Long-horizon agent results depend on the harness, tools, and reasoning budget.Custom licensing conditions apply to the weights.
Notable Use Cases
software engineering agentscoding assistantsresearch workflows
Function Calling Support
Yes
Tool Use Support
Yes

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