Claude 3.5 Sonnet (upgraded) vs Kimi K2 Thinking
Anthropic Claude 3.5 Sonnet (upgraded) | Moonshot AI Kimi K2 Thinking | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Oct 22 2024 | Nov 6 2025 |
| Access | Proprietary | Open Weight |
| Specifications | ||
Parameters | — | 1T |
Context window | — | 256k |
| Benchmarks | ||
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. | 49% | 71.3%Best |
| Timeline | ||
| Release gap | Claude 3.5 Sonnet (upgraded) shipped 380 days before Kimi K2 Thinking | |
Which is better: Claude 3.5 Sonnet (upgraded) or Kimi K2 Thinking?
Kimi K2 Thinking leads Claude 3.5 Sonnet (upgraded) on 1 of the 1 benchmark they both report (SWE-Bench Verified). Claude 3.5 Sonnet (upgraded) shipped 380 days before Kimi K2 Thinking, so benchmark comparisons should account for the intervening progress.
Claude 3.5 Sonnet (upgraded) is proprietary, while Kimi K2 Thinking is open weight.
On SWE-Bench Verified, Kimi K2 Thinking leads at 71.3% vs Claude 3.5 Sonnet (upgraded) at 49%.
Frequently asked questions
Claude 3.5 Sonnet (upgraded) was released by Anthropic on Oct 22 2024.
Kimi K2 Thinking was released by Moonshot AI on Nov 6 2025.
Kimi K2 Thinking leads on SWE-Bench Verified — Claude 3.5 Sonnet (upgraded) 49% vs Kimi K2 Thinking 71.3%.
Claude 3.5 Sonnet (upgraded) is a proprietary model released by Anthropic. Kimi K2 Thinking is an open weight model released by Moonshot AI.