GPT-5.3-Codex vs GLM-5.1
OpenAI GPT-5.3-Codex | Z.ai GLM-5.1 | |
|---|---|---|
| Overview | ||
| Company | OpenAI | Z.ai |
| Release date | Feb 5 2026 | Apr 7 2026 |
| Access | Proprietary | Open Weight |
| Specifications | ||
Parameters | — | 744B |
Context window | — | 200k |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 24% | — |
Agentic terminal coding Terminal-Bench 2.0Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? (Version 2.0 of the test.) Higher is better. | — | 63.5% |
Web browsing BrowseCompCan the AI browse the web and track down hard-to-find answers? Higher is better. | — | 68% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | — | 86.2% |
| Timeline | ||
| Release gap | GPT-5.3-Codex shipped 61 days before GLM-5.1 | |
Which is better: GPT-5.3-Codex or GLM-5.1?
GPT-5.3-Codex and GLM-5.1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GPT-5.3-Codex shipped 61 days before GLM-5.1, so benchmark comparisons should account for the intervening progress.
GPT-5.3-Codex is proprietary, while GLM-5.1 is open weight.
Direct benchmark comparisons are unavailable — GPT-5.3-Codex and GLM-5.1 don't publish scores on any of the same benchmarks.
Frequently asked questions
GPT-5.3-Codex was released by OpenAI on Feb 5 2026.
GLM-5.1 was released by Z.ai on Apr 7 2026.
GPT-5.3-Codex is a proprietary model released by OpenAI. GLM-5.1 is an open weight model released by Z.ai.
Other comparisons
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