Grok 4 Fast vs GLM-4.5
xAI Grok 4 Fast | Z.ai GLM-4.5 | |
|---|---|---|
| Overview | ||
| Company | xAI | Z.ai |
| Release date | Sep 2025 | Jul 28 2025 |
| Access | Proprietary | Open Weight |
| Specifications | ||
Parameters | — | 355B |
Context window | — | 128k |
| Benchmarks | ||
Coding SWE-Bench VerifiedReal coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | — | 64.2% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | — | 79.1% |
| Timeline | ||
| Release gap | GLM-4.5 shipped 35 days before Grok 4 Fast | |
Which is better: Grok 4 Fast or GLM-4.5?
Grok 4 Fast and GLM-4.5 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GLM-4.5 shipped 35 days before Grok 4 Fast, so benchmark comparisons should account for the intervening progress.
Grok 4 Fast is proprietary, while GLM-4.5 is open weight.
Direct benchmark comparisons are unavailable — Grok 4 Fast and GLM-4.5 don't publish scores on any of the same benchmarks.
Frequently asked questions
Grok 4 Fast was released by xAI on Sep 2025.
GLM-4.5 was released by Z.ai on Jul 28 2025.
Grok 4 Fast is a proprietary model released by xAI. GLM-4.5 is an open weight model released by Z.ai.
Other comparisons
Grok 4 Fast vs Claude Fable 5GLM-4.5 vs Claude Fable 5Grok 4 Fast vs GPT-5.6 SolGLM-4.5 vs GPT-5.6 SolGrok 4 Fast vs Gemini OmniGLM-4.5 vs Gemini OmniGrok 4 Fast vs Muse SparkGLM-4.5 vs Muse SparkGrok 4 Fast vs DeepSeek-V4-ProGLM-4.5 vs DeepSeek-V4-ProGrok 4 Fast vs Mistral Medium 3.5GLM-4.5 vs Mistral Medium 3.5