When was Claude 3 Sonnet released?

Claude 3 Sonnet was released by Anthropic on Mar 4 2024.

When was Kimi K2 (0905) released?

Kimi K2 (0905) was released by Moonshot AI on Sep 5 2025.

Which is better on GPQA Diamond, Claude 3 Sonnet or Kimi K2 (0905)?

Kimi K2 (0905) scores higher on GPQA Diamond — Claude 3 Sonnet 40.4% vs Kimi K2 (0905) 75.1%.

Is Claude 3 Sonnet or Kimi K2 (0905) open source?

Kimi K2 (0905) is an open-source / open-weight model released by Moonshot AI. Claude 3 Sonnet is a proprietary model released by Anthropic.

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Home/Compare/Claude 3 Sonnet vs Kimi K2 (0905)

Claude 3 Sonnet vs Kimi K2 (0905)

0 vs 2 benchmarks won

	Anthropic Claude 3 Sonnet	Moonshot AI Kimi K2 (0905)
Overview
Company	Anthropic	Moonshot AI
Release date	Mar 4 2024	Sep 5 2025
Model type	—	—
Open source	No	Yes
Specifications
Parameters	—	1T
Context window	—	256k
Benchmarks
Science reasoning GPQA Diamond	40.4%	75.1%
Software engineering SWE-Bench Verified	—	65.8%
Multimodal understanding MMMU	—	—
Timeline
Release gap	Claude 3 Sonnet shipped 550 days before Kimi K2 (0905)

Which is better: Claude 3 Sonnet or Kimi K2 (0905)?

Kimi K2 (0905) leads Claude 3 Sonnet on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). Claude 3 Sonnet shipped 550 days before Kimi K2 (0905), so benchmark comparisons should account for the intervening progress.

Kimi K2 (0905) is an open-source / open-weight model; Claude 3 Sonnet is proprietary.

On GPQA Diamond, Kimi K2 (0905) scores 75.1%, 34.7 points above Claude 3 Sonnet at 40.4%.

Frequently asked questions

When was Claude 3 Sonnet released?: Claude 3 Sonnet was released by Anthropic on Mar 4 2024.
When was Kimi K2 (0905) released?: Kimi K2 (0905) was released by Moonshot AI on Sep 5 2025.
Which is better on GPQA Diamond, Claude 3 Sonnet or Kimi K2 (0905)?: Kimi K2 (0905) scores higher on GPQA Diamond — Claude 3 Sonnet 40.4% vs Kimi K2 (0905) 75.1%.
Is Claude 3 Sonnet or Kimi K2 (0905) open source?: Kimi K2 (0905) is an open-source / open-weight model released by Moonshot AI. Claude 3 Sonnet is a proprietary model released by Anthropic.