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Claude Sonnet 4 vs Kimi K2 Thinking

2 vs 0 benchmarks won

Anthropic
Claude Sonnet 4
Moonshot AI
Kimi K2 Thinking
Overview
CompanyAnthropicMoonshot AI
Release dateMay 22 2025Nov 6 2025
Model type
Open sourceNoYes
Specifications
Parameters
1T
Context window
256k
Benchmarks
Science reasoning
GPQA Diamond
75.4%
Software engineering
SWE-Bench Verified
72.7%
71.3%
Multimodal understanding
MMMU
Timeline
Release gapClaude Sonnet 4 shipped 168 days before Kimi K2 Thinking

Which is better: Claude Sonnet 4 or Kimi K2 Thinking?

Claude Sonnet 4 leads Kimi K2 Thinking on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). Claude Sonnet 4 shipped 168 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 Sonnet 4 is proprietary.

On SWE-Bench Verified, Claude Sonnet 4 scores 72.7%, 1.4 points above Kimi K2 Thinking at 71.3%.

Frequently asked questions

When was Claude Sonnet 4 released?
Claude Sonnet 4 was released by Anthropic on May 22 2025.
When was Kimi K2 Thinking released?
Kimi K2 Thinking was released by Moonshot AI on Nov 6 2025.
Which is better at coding, Claude Sonnet 4 or Kimi K2 Thinking?
On SWE-Bench Verified (real-world software-engineering tasks), Claude Sonnet 4 leads — Claude Sonnet 4 scores 72.7% and Kimi K2 Thinking scores 71.3%.
Is Claude Sonnet 4 or Kimi K2 Thinking open source?
Kimi K2 Thinking is an open-source / open-weight model released by Moonshot AI. Claude Sonnet 4 is a proprietary model released by Anthropic.

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