Claude 3 SonnetvsKimi K2.5
Claude 3 Sonnet | Kimi K2.5 | |
|---|---|---|
| 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. | — | 52% |
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. | — | 76.8% |
Agentic coding CursorBench v3.1Cursor's own test of harder, real-world coding tasks inside a code editor. Higher is better. | — | 31.9% |
Next.js coding Next.js EvalsVercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. | — | 21% |
Competitive coding LiveCodeBenchCoding problems published so recently the AI can't have seen them in training — a contamination-free test of raw programming skill. Higher is better. | — | 85% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 40.4% | 87.6%Best |
Community preference (code) Arena Elo (Code)Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better. | — | 1433 |
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Mar 4 2024 | Jan 27 2026 |
| Access | Proprietary | Open Weight |
Which is better: Claude 3 Sonnet or Kimi K2.5?
Kimi K2.5 leads Claude 3 Sonnet on 1 of the 1 benchmark they both report (GPQA Diamond). Claude 3 Sonnet shipped 694 days before Kimi K2.5, so benchmark comparisons should account for the intervening progress.
Claude 3 Sonnet is proprietary, while Kimi K2.5 is open weight.
On GPQA Diamond, Kimi K2.5 leads at 87.6% vs Claude 3 Sonnet at 40.4%.
Frequently asked questions
Claude 3 Sonnet was released by Anthropic on Mar 4 2024.
Kimi K2.5 was released by Moonshot AI on Jan 27 2026.
Kimi K2.5 leads on GPQA Diamond — Claude 3 Sonnet 40.4% vs Kimi K2.5 87.6%.
Claude 3 Sonnet is a proprietary model released by Anthropic. Kimi K2.5 is an open weight model released by Moonshot AI.
Other comparisons
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