Kimi K2 Thinking vs o3
Moonshot AI Kimi K2 Thinking | OpenAI o3 | |
|---|---|---|
| Overview | ||
| Company | Moonshot AI | OpenAI |
| Release date | Nov 6 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. | 71.3% | — |
| Timeline | ||
| Release gap | o3 shipped 204 days before Kimi K2 Thinking | |
Which is better: Kimi K2 Thinking or o3?
Kimi K2 Thinking and o3 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o3 shipped 204 days before Kimi K2 Thinking, so benchmark comparisons should account for the intervening progress.
Kimi K2 Thinking is open weight, while o3 is proprietary.
Direct benchmark comparisons are unavailable — Kimi K2 Thinking and o3 don't publish scores on any of the same benchmarks.
Frequently asked questions
Kimi K2 Thinking was released by Moonshot AI on Nov 6 2025.
o3 was released by OpenAI on Apr 16 2025.
Kimi K2 Thinking is an open weight model released by Moonshot AI. o3 is a proprietary model released by OpenAI.
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