Claude 3.5 HaikuvsKimi K2.5
Claude 3.5 Haiku | 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. | 50% | 52%Best |
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. | 40.6% | 76.8%Best |
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. | 41.6% | 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 | Oct 22 2024 | Jan 27 2026 |
| Access | Proprietary | Open Weight |
Which is better: Claude 3.5 Haiku or Kimi K2.5?
Kimi K2.5 leads Claude 3.5 Haiku on 3 of the 3 benchmarks they both report (BullshitBench v2, SWE-Bench Verified, GPQA Diamond). Claude 3.5 Haiku shipped 462 days before Kimi K2.5, so benchmark comparisons should account for the intervening progress.
Claude 3.5 Haiku is proprietary, while Kimi K2.5 is open weight.
On BullshitBench v2, Kimi K2.5 leads at 52% vs Claude 3.5 Haiku at 50%. On SWE-Bench Verified, Kimi K2.5 leads at 76.8% vs Claude 3.5 Haiku at 40.6%. On GPQA Diamond, Kimi K2.5 leads at 87.6% vs Claude 3.5 Haiku at 41.6%.
Frequently asked questions
Claude 3.5 Haiku was released by Anthropic on Oct 22 2024.
Kimi K2.5 was released by Moonshot AI on Jan 27 2026.
Kimi K2.5 leads on SWE-Bench Verified — Claude 3.5 Haiku 40.6% vs Kimi K2.5 76.8%.
Kimi K2.5 leads on GPQA Diamond — Claude 3.5 Haiku 41.6% vs Kimi K2.5 87.6%.
Claude 3.5 Haiku is a proprietary model released by Anthropic. Kimi K2.5 is an open weight model released by Moonshot AI.