Claude 2.1vsKimi K2
Claude 2.1 | Kimi K2 | |
|---|---|---|
| Specifications | ||
Parameters | — | 1T |
Context window | 200k | 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% |
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Nov 21 2023 | Jul 11 2025 |
| Access | Proprietary | Open Weight |
Which is better: Claude 2.1 or Kimi K2?
Claude 2.1 and Kimi K2 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 2.1 shipped 598 days before Kimi K2, so benchmark comparisons should account for the intervening progress.
Context windows are 200k (Claude 2.1) vs 128k (Kimi K2). Claude 2.1 is proprietary, while Kimi K2 is open weight.
Direct benchmark comparisons are unavailable — Claude 2.1 and Kimi K2 don't publish scores on any of the same benchmarks.
Frequently asked questions
Claude 2.1 was released by Anthropic on Nov 21 2023.
Kimi K2 was released by Moonshot AI on Jul 11 2025.
Claude 2.1 has a 200k context window; Kimi K2 has 128k.
Claude 2.1 is a proprietary model released by Anthropic. Kimi K2 is an open weight model released by Moonshot AI.
Other comparisons
Claude 2.1vsGPT-5.6-CyberKimi K2vsGPT-5.6-CyberClaude 2.1vsGemini 3.7 FlashKimi K2vsGemini 3.7 FlashClaude 2.1vsMuse GlimmerKimi K2vsMuse GlimmerClaude 2.1vsGrok 4.6Kimi K2vsGrok 4.6Claude 2.1vsDeepSeek-V4-Pro-0813Kimi K2vsDeepSeek-V4-Pro-0813Claude 2.1vsMistral Medium 3.5Kimi K2vsMistral Medium 3.5