2 vs 0 benchmarks won
Anthropic Claude Haiku 4.5 | OpenAI gpt-oss-120b | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Oct 15 2025 | Aug 5 2025 |
| Model type | — | — |
| Open source | No | Yes |
| Specifications | ||
Parameters | — | — |
Context window | — | — |
| Benchmarks | ||
Science reasoning GPQA Diamond | 73% | — |
Software engineering SWE-Bench Verified | 73.3% | — |
Multimodal understanding MMMU | — | — |
| Timeline | ||
| Release gap | gpt-oss-120b shipped 71 days before Claude Haiku 4.5 | |
Claude Haiku 4.5 leads gpt-oss-120b on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). gpt-oss-120b shipped 71 days before Claude Haiku 4.5, so benchmark comparisons should account for the intervening progress.
gpt-oss-120b is an open-source / open-weight model; Claude Haiku 4.5 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.