Claude 3.5 Haiku vs Kimi K2 (0905)
Anthropic Claude 3.5 Haiku | Moonshot AI Kimi K2 (0905) | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Oct 22 2024 | Sep 5 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. | 50% | — |
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% | 65.8%Best |
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% | 75.1%Best |
| Timeline | ||
| Release gap | Claude 3.5 Haiku shipped 318 days before Kimi K2 (0905) | |
Which is better: Claude 3.5 Haiku or Kimi K2 (0905)?
Kimi K2 (0905) leads Claude 3.5 Haiku on 2 of the 2 benchmarks they both report (SWE-Bench Verified, GPQA Diamond). Claude 3.5 Haiku shipped 318 days before Kimi K2 (0905), so benchmark comparisons should account for the intervening progress.
Claude 3.5 Haiku is proprietary, while Kimi K2 (0905) is open weight.
On SWE-Bench Verified, Kimi K2 (0905) leads at 65.8% vs Claude 3.5 Haiku at 40.6%. On GPQA Diamond, Kimi K2 (0905) leads at 75.1% 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 (0905) was released by Moonshot AI on Sep 5 2025.
Kimi K2 (0905) leads on SWE-Bench Verified — Claude 3.5 Haiku 40.6% vs Kimi K2 (0905) 65.8%.
Kimi K2 (0905) leads on GPQA Diamond — Claude 3.5 Haiku 41.6% vs Kimi K2 (0905) 75.1%.
Claude 3.5 Haiku is a proprietary model released by Anthropic. Kimi K2 (0905) is an open weight model released by Moonshot AI.