Kimi K2 (0905) vs o3
Moonshot AI Kimi K2 (0905) | OpenAI o3 | |
|---|---|---|
| Overview | ||
| Company | Moonshot AI | OpenAI |
| Release date | Sep 5 2025 | Apr 16 2025 |
| Access | Open Weight | Proprietary |
| Specifications | ||
Parameters | 1T | — |
Context window | 256k | — |
| 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. | — | 26% |
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 | o3 shipped 142 days before Kimi K2 (0905) | |
Which is better: Kimi K2 (0905) or o3?
Kimi K2 (0905) and o3 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o3 shipped 142 days before Kimi K2 (0905), so benchmark comparisons should account for the intervening progress.
Kimi K2 (0905) is open weight, while o3 is proprietary.
Direct benchmark comparisons are unavailable — Kimi K2 (0905) and o3 don't publish scores on any of the same benchmarks.
Frequently asked questions
Kimi K2 (0905) was released by Moonshot AI on Sep 5 2025.
o3 was released by OpenAI on Apr 16 2025.
Kimi K2 (0905) is an open weight model released by Moonshot AI. o3 is a proprietary model released by OpenAI.
Other comparisons
Kimi K2 (0905) vs Claude Sonnet 5o3 vs Claude Sonnet 5Kimi K2 (0905) vs Gemini Omnio3 vs Gemini OmniKimi K2 (0905) vs Muse Spark 1.1o3 vs Muse Spark 1.1Kimi K2 (0905) vs Grok 4.5o3 vs Grok 4.5Kimi K2 (0905) vs DeepSeek-V4-Proo3 vs DeepSeek-V4-ProKimi K2 (0905) vs Mistral Medium 3.5o3 vs Mistral Medium 3.5