Anthropic Claude 2.1 vs OpenAI gpt-oss-20b — side-by-side specs.
Anthropic Claude 2.1 | OpenAI gpt-oss-20b | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Nov 21 2023 | Aug 5 2025 |
| Model type | — | — |
| Open source | No | Yes |
| Specifications | ||
Parameters | — | — |
Context window | — | — |
| Benchmarks | ||
Science reasoning GPQA Diamond | — | — |
Software engineering SWE-Bench Verified | — | — |
Multimodal understanding MMMU | — | — |
| Timeline | ||
| Release gap | Claude 2.1 shipped 623 days before gpt-oss-20b | |
Claude 2.1 and gpt-oss-20b do not have directly comparable benchmark scores published on GPQA Diamond, SWE-Bench Verified, or MMMU. Claude 2.1 shipped 623 days before gpt-oss-20b, so benchmark comparisons should account for the intervening progress.
gpt-oss-20b is an open-source / open-weight model; Claude 2.1 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.