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Claude Sonnet 4.5 vs Kimi-Dev

Anthropic Claude Sonnet 4.5 vs Moonshot AI Kimi-Dev — side-by-side specs.

Anthropic
Claude Sonnet 4.5
Moonshot AI
Kimi-Dev
Overview
CompanyAnthropicMoonshot AI
Release dateSep 29 2025Jun 2025
Model type
Open sourceNoYes
Specifications
Parameters
72B
Context window
Benchmarks
Coding
SWE-Bench Verified
77.2%
Science
GPQA Diamond
83.4%
Multimodal
MMMU
68%
Timeline
Release gapKimi-Dev shipped 120 days before Claude Sonnet 4.5

Which is better: Claude Sonnet 4.5 or Kimi-Dev?

Claude Sonnet 4.5 and Kimi-Dev don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Kimi-Dev shipped 120 days before Claude Sonnet 4.5, so benchmark comparisons should account for the intervening progress.

Kimi-Dev is an open-source / open-weight model; Claude Sonnet 4.5 is proprietary.

Direct benchmark comparisons are unavailable — Claude Sonnet 4.5 and Kimi-Dev don't publish scores on any of the same benchmarks.

Frequently asked questions

When was Claude Sonnet 4.5 released?
Claude Sonnet 4.5 was released by Anthropic on Sep 29 2025.
When was Kimi-Dev released?
Kimi-Dev was released by Moonshot AI on Jun 2025.
Is Claude Sonnet 4.5 or Kimi-Dev open source?
Kimi-Dev is an open-source / open-weight model released by Moonshot AI. Claude Sonnet 4.5 is a proprietary model released by Anthropic.

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