Lab system cards and frameworks · System card · Anthropic

System Card: Claude Opus 4 & Claude Sonnet 4

22 May 2025

This is version r3. The latest is r4.

Outline

The outline is kept for the latest version, r4. Open at p. 1

How to cite

A citation names the document, the version and the place.

anthropic:claude-4-system-card/r3/p1

https://safetypage.noahairmet.com/d/anthropic/claude-4-system-card/r3/p1

BibTeX

@misc{anthropic2025,
  title = {System Card: Claude Opus 4 & Claude Sonnet 4},
  author = {{Anthropic}},
  year = {2025},
  url = {https://www-cdn.anthropic.com/6d8a8055020700718b0c49369f60816ba2a7c285.pdf}
}

Versions

Version	Published	Read
r4 latest	16 Jul 2025	At source
r3	22 May 2025	At source
r2	22 May 2025	At source
r1	22 May 2025	At source

Licence

So you: Search it, cite it and check quotes here; read it at its source