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 every image it finds

TEXTAPI ANNOUNCED

Anthropic's detection API isn't live yet

Drop files here, or click to choose

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