2 vs 0 benchmarks won
Anthropic Claude Sonnet 4 | Moonshot AI Kimi K2 | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | May 22 2025 | Jul 11 2025 |
| Model type | — | — |
| Open source | No | Yes |
| Specifications | ||
Parameters | — | 1T |
Context window | — | 128k |
| Benchmarks | ||
Coding SWE-Bench VerifiedReal coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | 72.7%Best | 65.8% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 75.4%Best | 75.1% |
| Timeline | ||
| Release gap | Claude Sonnet 4 shipped 50 days before Kimi K2 | |
Claude Sonnet 4 leads Kimi K2 on 2 of the 2 benchmarks they both report (SWE-Bench Verified, GPQA Diamond). Claude Sonnet 4 shipped 50 days before Kimi K2, so benchmark comparisons should account for the intervening progress.
Kimi K2 is an open-source / open-weight model; Claude Sonnet 4 is proprietary.
On SWE-Bench Verified, Claude Sonnet 4 leads at 72.7% vs Kimi K2 at 65.8%. On GPQA Diamond, Claude Sonnet 4 leads at 75.4% vs Kimi K2 at 75.1%.