OpenAI gpt-oss-20b vs xAI Grok 4.1 Fast — side-by-side specs.
OpenAI gpt-oss-20b | xAI Grok 4.1 Fast | |
|---|---|---|
| Overview | ||
| Company | OpenAI | xAI |
| Release date | Aug 5 2025 | Nov 19 2025 |
| Model type | — | — |
| Open source | Yes | No |
| Specifications | ||
Parameters | — | — |
Context window | — | — |
| Benchmarks | ||
Science reasoning GPQA Diamond | — | — |
Software engineering SWE-Bench Verified | — | — |
Multimodal understanding MMMU | — | — |
| Timeline | ||
| Release gap | gpt-oss-20b shipped 106 days before Grok 4.1 Fast | |
gpt-oss-20b and Grok 4.1 Fast do not have directly comparable benchmark scores published on GPQA Diamond, SWE-Bench Verified, or MMMU. gpt-oss-20b shipped 106 days before Grok 4.1 Fast, so benchmark comparisons should account for the intervening progress.
gpt-oss-20b is an open-source / open-weight model; Grok 4.1 Fast is proprietary.
Direct benchmark comparisons are unavailable — at least one of these models has not published scores on GPQA Diamond, SWE-Bench Verified, or MMMU.