# GLM-5.3 Prime spotted on Alibaba Model Studio API

GLM-5.3 Prime from Z.ai was first recorded on 21 Sep 2026. Its release date is not established. Catalogues list a 1,000,000 tokens context window. 2 evidence links.

- Kind: Sighting
- Developer: Z.ai
- Confidence: Confirmed
- First seen: 2026-09-21T03:28:36.335Z
- Model: [GLM-5.3 Prime](https://alexgetman.com/models/z-ai/glm-5-3-prime/)
- Canonical: https://alexgetman.com/signals/2026/09/21/z-ai-glm-5-3-prime-20260921/

## Evidence links

- [Alibaba Model Studio API](https://www.alibabacloud.com/help/en/model-studio/models)
- [OpenRouter](https://openrouter.ai/z-ai/glm-5.3-prime)