Claude Opus 4.5 vs Kimi K2 Thinking
Anthropic Claude Opus 4.5 | Moonshot AI Kimi K2 Thinking | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Nov 24 2025 | Nov 6 2025 |
| Access | Proprietary | Open Weight |
| 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. | 90% | — |
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. | 80.9%Best | 71.3% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 87% | — |
| Timeline | ||
| Release gap | Kimi K2 Thinking shipped 18 days before Claude Opus 4.5 | |
Which is better: Claude Opus 4.5 or Kimi K2 Thinking?
Claude Opus 4.5 leads Kimi K2 Thinking on 1 of the 1 benchmark they both report (SWE-Bench Verified). Kimi K2 Thinking shipped 18 days before Claude Opus 4.5, so benchmark comparisons should account for the intervening progress.
Claude Opus 4.5 is proprietary, while Kimi K2 Thinking is open weight.
On SWE-Bench Verified, Claude Opus 4.5 leads at 80.9% vs Kimi K2 Thinking at 71.3%.
Frequently asked questions
Claude Opus 4.5 was released by Anthropic on Nov 24 2025.
Kimi K2 Thinking was released by Moonshot AI on Nov 6 2025.
Claude Opus 4.5 leads on SWE-Bench Verified — Claude Opus 4.5 80.9% vs Kimi K2 Thinking 71.3%.
Claude Opus 4.5 is a proprietary model released by Anthropic. Kimi K2 Thinking is an open weight model released by Moonshot AI.
Other comparisons
Claude Opus 4.5 vs GPT-5.6 SolKimi K2 Thinking vs GPT-5.6 SolClaude Opus 4.5 vs Gemini OmniKimi K2 Thinking vs Gemini OmniClaude Opus 4.5 vs Muse Spark 1.1Kimi K2 Thinking vs Muse Spark 1.1Claude Opus 4.5 vs Grok 4.5Kimi K2 Thinking vs Grok 4.5Claude Opus 4.5 vs DeepSeek-V4-ProKimi K2 Thinking vs DeepSeek-V4-ProClaude Opus 4.5 vs Mistral Medium 3.5Kimi K2 Thinking vs Mistral Medium 3.5