GLM-5.3
GLM-5.3 is Z.ai's post-trained coding and agent model built on the same base model as GLM-5.2. Z.ai positions it for complex coding, long-horizon tasks, and cybersecurity evaluation, with mandatory thinking, low, high, and max reasoning effort, and availability through GLM Coding Plan and ZCode at launch.
Provider
Z.ai
Model family
Z.ai GLM
Coding and agentic reasoning LLM
Cost tier
Flagship
Status
Current
Release Aug 14, 2026
Why teams choose it
Z.ai says GLM-5.3 keeps the GLM-5.2 base model and obtains its gains from additional post-training.
Z.ai says GLM-5.3 keeps the GLM-5.2 base model and obtains its gains from additional post-training.
The launch supports low, high, and max reasoning effort and does not support disabling thinking.
The launch supports low, high, and max reasoning effort and does not support disabling thinking.
Initial access is through GLM Coding Plan and ZCode; the announcement says downloadable…
weights will follow after safety hardening.
Tradeoffs to know
- Open weights, their final license, and broad direct API availability were not live at announcement time.
- Cybersecurity claims and all benchmark scores are vendor-reported and should be handled with controlled access and independent evaluation.
- Mandatory thinking and long output budgets can materially affect latency, quota usage, and task cost.
When not to use this
- Not ideal for simple tasks where cheaper models in the same lineup are good enough.
- Avoid for regulated or high-stakes outputs without evaluations that mimic your tooling, data, and review process.
- Pair catalog notes with comparisons and your own benchmarks before declaring a routing winner.
Technical specs
- Inputs
- text
- Outputs
- text
- Capabilities
- coding, long-horizon agents, reasoning, terminal workflows, codebase analysis, tool use, cybersecurity evaluation
- License
- Hosted access at launch; open-weight license pending
- Model string
glm-5-3
Benchmarks
{
"source": "https://z.ai/blog/glm-5.3",
"deep_swe_v1_1": 66.9,
"vendor_reported": true,
"terminal_bench_3": 28.3
}Z.ai GLM family lineup
Previous versions
Compare with
GLM-5.3 FAQ
What is GLM-5.3?
GLM-5.3 is Z.ai's post-trained coding and agent model built on the same base model as GLM-5.2. Z.ai positions it for complex coding, long-horizon tasks, and cybersecurity evaluation, with mandatory thinking, low, high, and max reasoning effort, and availability through GLM Coding Plan and ZCode at launch.
When does GLM-5.3 fit best?
Complex repository coding
What should teams watch out for with GLM-5.3?
Open weights, their final license, and broad direct API availability were not live at announcement time.
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