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Claude 3.5 Sonnet vs Kimi K2 Thinking

1 vs 1 benchmarks won

Anthropic
Claude 3.5 Sonnet
Moonshot AI
Kimi K2 Thinking
Overview
CompanyAnthropicMoonshot AI
Release dateJun 20 2024Nov 6 2025
Model type
Open sourceNoYes
Specifications
Parameters
1T
Context window
256k
Benchmarks
Science reasoning
GPQA Diamond
59.4%
Software engineering
SWE-Bench Verified
33.4%
71.3%
Multimodal understanding
MMMU
Timeline
Release gapClaude 3.5 Sonnet shipped 504 days before Kimi K2 Thinking

Which is better: Claude 3.5 Sonnet or Kimi K2 Thinking?

Claude 3.5 Sonnet and Kimi K2 Thinking are evenly matched across the benchmarks they both publish. Claude 3.5 Sonnet shipped 504 days before Kimi K2 Thinking, so benchmark comparisons should account for the intervening progress.

Kimi K2 Thinking is an open-source / open-weight model; Claude 3.5 Sonnet is proprietary.

On SWE-Bench Verified, Kimi K2 Thinking scores 71.3%, 37.9 points above Claude 3.5 Sonnet at 33.4%.

Frequently asked questions

When was Claude 3.5 Sonnet released?
Claude 3.5 Sonnet was released by Anthropic on Jun 20 2024.
When was Kimi K2 Thinking released?
Kimi K2 Thinking was released by Moonshot AI on Nov 6 2025.
Which is better at coding, Claude 3.5 Sonnet or Kimi K2 Thinking?
On SWE-Bench Verified (real-world software-engineering tasks), Kimi K2 Thinking leads — Claude 3.5 Sonnet scores 33.4% and Kimi K2 Thinking scores 71.3%.
Is Claude 3.5 Sonnet or Kimi K2 Thinking open source?
Kimi K2 Thinking is an open-source / open-weight model released by Moonshot AI. Claude 3.5 Sonnet is a proprietary model released by Anthropic.

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