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Claude Opus 4.1 vs Kimi K2.5

0 vs 2 benchmarks won

Anthropic
Claude Opus 4.1
Moonshot AI
Kimi K2.5
Overview
CompanyAnthropicMoonshot AI
Release dateAug 5 2025Jan 27 2026
Model type
Open sourceNoYes
Specifications
Parameters
1T
Context window
256k
Benchmarks
Science reasoning
GPQA Diamond
80.9%
87.6%
Software engineering
SWE-Bench Verified
74.5%
76.8%
Multimodal understanding
MMMU
Timeline
Release gapClaude Opus 4.1 shipped 175 days before Kimi K2.5

Which is better: Claude Opus 4.1 or Kimi K2.5?

Kimi K2.5 leads Claude Opus 4.1 on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). Claude Opus 4.1 shipped 175 days before Kimi K2.5, so benchmark comparisons should account for the intervening progress.

Kimi K2.5 is an open-source / open-weight model; Claude Opus 4.1 is proprietary.

On GPQA Diamond, Kimi K2.5 scores 87.6%, 6.7 points above Claude Opus 4.1 at 80.9%. On SWE-Bench Verified, Kimi K2.5 scores 76.8%, 2.3 points above Claude Opus 4.1 at 74.5%.

Frequently asked questions

When was Claude Opus 4.1 released?
Claude Opus 4.1 was released by Anthropic on Aug 5 2025.
When was Kimi K2.5 released?
Kimi K2.5 was released by Moonshot AI on Jan 27 2026.
Which is better on GPQA Diamond, Claude Opus 4.1 or Kimi K2.5?
Kimi K2.5 scores higher on GPQA Diamond — Claude Opus 4.1 80.9% vs Kimi K2.5 87.6%.
Which is better at coding, Claude Opus 4.1 or Kimi K2.5?
On SWE-Bench Verified (real-world software-engineering tasks), Kimi K2.5 leads — Claude Opus 4.1 scores 74.5% and Kimi K2.5 scores 76.8%.
Is Claude Opus 4.1 or Kimi K2.5 open source?
Kimi K2.5 is an open-source / open-weight model released by Moonshot AI. Claude Opus 4.1 is a proprietary model released by Anthropic.

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