Provenance check · C2PA + Claude watermark

Was this written by Claude?

Since August 2, 2026, new Claude models mark what they make: signed C2PA metadata on files, a SynthID-family statistical watermark woven into text — readable only with Anthropic's key. Drop a specimen below and we look for those marks. Everything is verified in your browser — nothing you drop here is uploaded.

FILESLIVE

C2PA signature verification, in your browser

LINKSLIVE

fetches the page — checks images, source, and text tells

TEXTPRIVATE PREVIEW

Anthropic's detection API — eligible orgs only, no public access

Drop files here, or click to choose

Images, PDFs, video — checked locally, never uploaded · up to 6