Z.ai's flagship for coding and security review at the same price as 5.2, though the weights use Z.ai's own licence rather than MIT.
Kenning's take
What it does
GLM-5.3 is Z.ai's flagship text model, built on the same base as GLM-5.2 with more post-training. Z.ai reports a 50% gain over GLM-5.2 on its own coding benchmark and strong results at finding software vulnerabilities. It has a 1M-token context, always reasons, and is available via the Z.ai API, the GLM Coding Plan and as open weights under Z.ai's own licence.
- 1M-token context and 128K output
- Always-on reasoning with low, high and max effort
- Stronger coding than GLM-5.2
- Vulnerability discovery and code review
- Open weights under a GLM-5.3 licence
Who it suits. Developers and security teams wanting a high-end open-weights model for coding and code review.
Key facts
- Category
- AI models
- Made by
- Z.ai (Zhipu AI)
- Based in
- China
- Released
- 18 August 2026
- How to get it
- Z.ai API (model glm-5.3), GLM Coding Plan, or open weights on Hugging Face
- Works on
- API, open weights (Hugging Face)
- In the UK
- Yes
- API price
- $1.40 per million input tokens, $4.40 per million output tokens
Pricing
| Plan | Price | Billed |
|---|---|---|
| GLM Coding Plan | $from 18 | month |
Models and features
- GLM-5.3-Flash 2026-08-26
FAQ
When was GLM-5.3 released?
Z.ai listed GLM-5.3 in its release notes on 18 August 2026.
Is GLM-5.3 open source?
The weights are on Hugging Face under a custom GLM-5.3 licence rather than MIT.
How much does GLM-5.3 cost?
$1.40 per million input tokens and $4.40 per million output on the Z.ai API.
Facts from the maker's own pages and the sources listed. Checked 2026-10-11.
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