gpt-oss-120b vs Grok 4 Fast
OpenAI gpt-oss-120b | SpaceXAI Grok 4 Fast | |
|---|---|---|
| Overview | ||
| Company | OpenAI | SpaceXAI |
| Release date | Aug 5 2025 | Sep 2025 |
| Access | Open Weight | Proprietary |
| 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% | — |
| Timeline | ||
| Release gap | gpt-oss-120b shipped 27 days before Grok 4 Fast | |
Which is better: gpt-oss-120b or Grok 4 Fast?
gpt-oss-120b and Grok 4 Fast don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. gpt-oss-120b shipped 27 days before Grok 4 Fast, so benchmark comparisons should account for the intervening progress.
gpt-oss-120b is open weight, while Grok 4 Fast is proprietary.
Direct benchmark comparisons are unavailable — gpt-oss-120b and Grok 4 Fast don't publish scores on any of the same benchmarks.
Frequently asked questions
gpt-oss-120b was released by OpenAI on Aug 5 2025.
Grok 4 Fast was released by SpaceXAI on Sep 2025.
gpt-oss-120b is an open weight model released by OpenAI. Grok 4 Fast is a proprietary model released by SpaceXAI.
Other comparisons
gpt-oss-120b vs Claude Sonnet 5Grok 4 Fast vs Claude Sonnet 5gpt-oss-120b vs Gemini OmniGrok 4 Fast vs Gemini Omnigpt-oss-120b vs Muse Spark 1.1Grok 4 Fast vs Muse Spark 1.1gpt-oss-120b vs DeepSeek-V4-ProGrok 4 Fast vs DeepSeek-V4-Progpt-oss-120b vs Mistral Medium 3.5Grok 4 Fast vs Mistral Medium 3.5gpt-oss-120b vs Kimi K2.7 CodeGrok 4 Fast vs Kimi K2.7 Code