Kimi K2 vs o1
Moonshot AI Kimi K2 | OpenAI o1 | |
|---|---|---|
| Overview | ||
| Company | Moonshot AI | OpenAI |
| Release date | Jul 11 2025 | Dec 5 2024 |
| Access | Open Weight | Proprietary |
| Specifications | ||
Parameters | 1T | — |
Context window | 128k | — |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 10% | — |
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. | 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. | 75.1% | — |
| Timeline | ||
| Release gap | o1 shipped 218 days before Kimi K2 | |
Which is better: Kimi K2 or o1?
Kimi K2 and o1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o1 shipped 218 days before Kimi K2, so benchmark comparisons should account for the intervening progress.
Kimi K2 is open weight, while o1 is proprietary.
Direct benchmark comparisons are unavailable — Kimi K2 and o1 don't publish scores on any of the same benchmarks.
Frequently asked questions
Kimi K2 was released by Moonshot AI on Jul 11 2025.
o1 was released by OpenAI on Dec 5 2024.
Kimi K2 is an open weight model released by Moonshot AI. o1 is a proprietary model released by OpenAI.