When was Claude Opus 4.1 released?

Claude Opus 4.1 was released by Anthropic on Aug 5 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 Opus 4.1 or Kimi K2 Thinking?

Claude Opus 4.1 leads on SWE-Bench Verified — Claude Opus 4.1 74.5% vs Kimi K2 Thinking 71.3%.

Is Claude Opus 4.1 or Kimi K2 Thinking open source?

Kimi K2 Thinking is an open-source / open-weight model released by Moonshot AI. Claude Opus 4.1 is a proprietary model released by Anthropic.

Home Latest Analytics Contact

Latest Release

Claude Opus 4.8

May 28 2026

Home/Compare/Claude Opus 4.1 vs Kimi K2 Thinking

Claude Opus 4.1 vs Kimi K2 Thinking

1 vs 0 benchmarks won

	Anthropic Claude Opus 4.1	Moonshot AI Kimi K2 Thinking
Overview
Company	Anthropic	Moonshot AI
Release date	Aug 5 2025	Nov 6 2025
Model type	—	—
Open source	No	Yes
Specifications
Parameters	—	1T
Context window	—	256k
Benchmarks
Coding SWE-Bench Verified	74.5%Best	71.3%
Science GPQA Diamond	80.9%	—
Timeline
Release gap	Claude Opus 4.1 shipped 93 days before Kimi K2 Thinking

Which is better: Claude Opus 4.1 or Kimi K2 Thinking?

Claude Opus 4.1 leads Kimi K2 Thinking on 1 of the 1 benchmark they both report (SWE-Bench Verified). Claude Opus 4.1 shipped 93 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 Opus 4.1 is proprietary.

On SWE-Bench Verified, Claude Opus 4.1 leads at 74.5% vs Kimi K2 Thinking at 71.3%.

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 Thinking released?: Kimi K2 Thinking was released by Moonshot AI on Nov 6 2025.
Which is better at coding, Claude Opus 4.1 or Kimi K2 Thinking?: Claude Opus 4.1 leads on SWE-Bench Verified — Claude Opus 4.1 74.5% vs Kimi K2 Thinking 71.3%.
Is Claude Opus 4.1 or Kimi K2 Thinking open source?: Kimi K2 Thinking is an open-source / open-weight model released by Moonshot AI. Claude Opus 4.1 is a proprietary model released by Anthropic.