0 vs 2 benchmarks won
Moonshot AI Kimi K1.5 | Moonshot AI Kimi K2 (0905) | |
|---|---|---|
| Overview | ||
| Company | Moonshot AI | Moonshot AI |
| Release date | Jan 20 2025 | Sep 5 2025 |
| Model type | — | — |
| Open source | No | Yes |
| Specifications | ||
Parameters | — | 1T |
Context window | 128k | 256k |
| Benchmarks | ||
Science reasoning GPQA Diamond | — | 75.1% |
Software engineering SWE-Bench Verified | — | 65.8% |
Multimodal understanding MMMU | — | — |
| Timeline | ||
| Release gap | Kimi K1.5 shipped 228 days before Kimi K2 (0905) | |
Kimi K2 (0905) leads Kimi K1.5 on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). Kimi K1.5 shipped 228 days before Kimi K2 (0905), so benchmark comparisons should account for the intervening progress.
Context windows are 128k (Kimi K1.5) vs 256k (Kimi K2 (0905)). Kimi K2 (0905) is an open-source / open-weight model; Kimi K1.5 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.