1 vs 2 benchmarks won
Moonshot AI Kimi K2.5 | OpenAI GPT-5.1 | |
|---|---|---|
| Overview | ||
| Company | Moonshot AI | OpenAI |
| Release date | Jan 27 2026 | Nov 12 2025 |
| Model type | — | — |
| Open source | Yes | No |
| Specifications | ||
Parameters | 1T | — |
Context window | 256k | — |
| Benchmarks | ||
Science reasoning GPQA Diamond | 87.6% | 88.1% |
Software engineering SWE-Bench Verified | 76.8% | 76.3% |
Multimodal understanding MMMU | — | 76% |
| Timeline | ||
| Release gap | GPT-5.1 shipped 76 days before Kimi K2.5 | |
GPT-5.1 leads Kimi K2.5 on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). GPT-5.1 shipped 76 days before Kimi K2.5, so benchmark comparisons should account for the intervening progress.
Kimi K2.5 is an open-source / open-weight model; GPT-5.1 is proprietary.
On GPQA Diamond, GPT-5.1 scores 88.1%, 0.5 points above Kimi K2.5 at 87.6%. On SWE-Bench Verified, Kimi K2.5 scores 76.8%, 0.5 points above GPT-5.1 at 76.3%.