Grok 4.1 FastvsGLM-4.5
Grok 4.1 Fast | GLM-4.5 | |
|---|---|---|
| Specifications | ||
Parameters | — | 355B |
Context window | — | 128k |
| 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. | 19%Best | 8% |
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% |
| Overview | ||
| Company | SpaceXAI | Z.ai |
| Release date | Nov 19 2025 | Jul 28 2025 |
| Access | Proprietary | Open Weight |
Which is better: Grok 4.1 Fast or GLM-4.5?
Grok 4.1 Fast leads GLM-4.5 on 1 of the 1 benchmark they both report (BullshitBench v2). GLM-4.5 shipped 114 days before Grok 4.1 Fast, so benchmark comparisons should account for the intervening progress.
Grok 4.1 Fast is proprietary, while GLM-4.5 is open weight.
On BullshitBench v2, Grok 4.1 Fast leads at 19% vs GLM-4.5 at 8%.
Frequently asked questions
Grok 4.1 Fast was released by SpaceXAI on Nov 19 2025.
GLM-4.5 was released by Z.ai on Jul 28 2025.
Grok 4.1 Fast is a proprietary model released by SpaceXAI. GLM-4.5 is an open weight model released by Z.ai.
Other comparisons
Grok 4.1 FastvsClaude Opus 5GLM-4.5vsClaude Opus 5Grok 4.1 FastvsGPT-5.6 SolGLM-4.5vsGPT-5.6 SolGrok 4.1 FastvsGemini 3.6 FlashGLM-4.5vsGemini 3.6 FlashGrok 4.1 FastvsMuse Spark 1.2GLM-4.5vsMuse Spark 1.2Grok 4.1 FastvsDeepSeek-V4-Flash-0731GLM-4.5vsDeepSeek-V4-Flash-0731Grok 4.1 FastvsMistral Medium 3.5GLM-4.5vsMistral Medium 3.5