gpt-oss-120bvsGrok 4.1 Fast
gpt-oss-120b | Grok 4.1 Fast | |
|---|---|---|
| Specifications | ||
Parameters | 117B | — |
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. | 11% | 19%Best |
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. | 62.4% | — |
Multidisciplinary reasoning Humanity's Last Exam · no toolsHumanity's Last Exam — extremely hard expert questions across many subjects, written so you can't just look up the answer. “No tools” means the AI answers on its own. Higher is better. | 14.9% | — |
Multidisciplinary reasoning Humanity's Last Exam · with toolsHumanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better. | 19% | — |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 80.1% | — |
General knowledge MMLUA 57-subject multiple-choice exam — history, law, medicine, maths — that was the standard measure of how much a model knows from 2020 until roughly 2024, when frontier scores crowded into the high 80s and labs moved on to harder tests. The scores here were published years apart under different testing setups, so read them as a historical record rather than a like-for-like ranking. Higher is better. | 90% | — |
| Overview | ||
| Company | OpenAI | SpaceXAI |
| Release date | Aug 5 2025 | Nov 19 2025 |
| Access | Open Weight | Proprietary |
Which is better: gpt-oss-120b or Grok 4.1 Fast?
Grok 4.1 Fast leads gpt-oss-120b on 1 of the 1 benchmark they both report (BullshitBench v2). gpt-oss-120b shipped 106 days before Grok 4.1 Fast, so benchmark comparisons should account for the intervening progress.
gpt-oss-120b is open weight, while Grok 4.1 Fast is proprietary.
On BullshitBench v2, Grok 4.1 Fast leads at 19% vs gpt-oss-120b at 11%.
Frequently asked questions
gpt-oss-120b was released by OpenAI on Aug 5 2025.
Grok 4.1 Fast was released by SpaceXAI on Nov 19 2025.
gpt-oss-120b is an open weight model released by OpenAI. Grok 4.1 Fast is a proprietary model released by SpaceXAI.
Other comparisons
gpt-oss-120bvsClaude Opus 5Grok 4.1 FastvsClaude Opus 5gpt-oss-120bvsGemini 3.7 FlashGrok 4.1 FastvsGemini 3.7 Flashgpt-oss-120bvsMuse GlimmerGrok 4.1 FastvsMuse Glimmergpt-oss-120bvsDeepSeek-V4-Pro-0813Grok 4.1 FastvsDeepSeek-V4-Pro-0813gpt-oss-120bvsMistral Medium 3.5Grok 4.1 FastvsMistral Medium 3.5gpt-oss-120bvsKimi K3Grok 4.1 FastvsKimi K3