2 vs 0 benchmarks won
Anthropic Claude Opus 4.5 | Moonshot AI Kimi K2 | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Nov 24 2025 | Jul 11 2025 |
| Model type | — | — |
| Open source | No | Yes |
| Specifications | ||
Parameters | — | 1T |
Context window | — | 128k |
| Benchmarks | ||
Science reasoning GPQA Diamond | 87% | 75.1% |
Software engineering SWE-Bench Verified | 80.9% | 65.8% |
Multimodal understanding MMMU | — | — |
| Timeline | ||
| Release gap | Kimi K2 shipped 136 days before Claude Opus 4.5 | |
Claude Opus 4.5 leads Kimi K2 on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). Kimi K2 shipped 136 days before Claude Opus 4.5, so benchmark comparisons should account for the intervening progress.
Kimi K2 is an open-source / open-weight model; Claude Opus 4.5 is proprietary.
On GPQA Diamond, Claude Opus 4.5 scores 87%, 11.9 points above Kimi K2 at 75.1%. On SWE-Bench Verified, Claude Opus 4.5 scores 80.9%, 15.1 points above Kimi K2 at 65.8%.