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Claude Opus 4.8 vs Kimi K2 Thinking

Anthropic Claude Opus 4.8 vs Moonshot AI Kimi K2 Thinking — side-by-side specs.

Anthropic
Claude Opus 4.8
Moonshot AI
Kimi K2 Thinking
Overview
CompanyAnthropicMoonshot AI
Release dateMay 28 2026Nov 6 2025
Model type
Open sourceNoYes
Specifications
Parameters
1T
Context window
256k
Benchmarks
Agentic coding
SWE-Bench Pro
69.2%
Coding
SWE-Bench Verified
71.3%
Agentic terminal coding
Terminal-Bench 2.1
74.6%
Multidisciplinary reasoning
Humanity's Last Exam · no tools
49.8%
Multidisciplinary reasoning
Humanity's Last Exam · with tools
57.9%
Agentic computer use
OSWorld-Verified
83.4%
Agentic financial analysis
Finance Agent v2
53.9%
Knowledge work
GDPval-AA
1890
Timeline
Release gapKimi K2 Thinking shipped 203 days before Claude Opus 4.8

Which is better: Claude Opus 4.8 or Kimi K2 Thinking?

Claude Opus 4.8 and Kimi K2 Thinking don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Kimi K2 Thinking shipped 203 days before Claude Opus 4.8, so benchmark comparisons should account for the intervening progress.

Kimi K2 Thinking is an open-source / open-weight model; Claude Opus 4.8 is proprietary.

Direct benchmark comparisons are unavailable — Claude Opus 4.8 and Kimi K2 Thinking don't publish scores on any of the same benchmarks.

Frequently asked questions

When was Claude Opus 4.8 released?
Claude Opus 4.8 was released by Anthropic on May 28 2026.
When was Kimi K2 Thinking released?
Kimi K2 Thinking was released by Moonshot AI on Nov 6 2025.
Is Claude Opus 4.8 or Kimi K2 Thinking open source?
Kimi K2 Thinking is an open-source / open-weight model released by Moonshot AI. Claude Opus 4.8 is a proprietary model released by Anthropic.

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