CLAUDE / C2PA CONTENT CREDENTIALS CHECKER
Upload an image or SVG to check whether it carries a signed C2PA provenance manifest — the same metadata Claude attaches to generated files. Paste text below to run a transparent stylistic heuristic. Everything runs in your browser; nothing is uploaded anywhere.
File Check — C2PA Manifest
Drag a file here, or
PNG, JPEG, SVG, WebP
What this checks: presence of C2PA manifest byte markers (JUMBF boxes, the PNG caBX chunk, XML manifest references) and best-effort extraction of readable manifest fields. It does not perform cryptographic signature or trust-chain validation. For an authoritative valid / tampered / no-data verdict backed by certificate verification, cross-check with Content Credentials Verify , the Content Authenticity Initiative's official verifier.
Text Check — Stylistic AI-Writing Heuristic
Paste text below to score it against four published, transparent stylistic signals — sentence-length burstiness, formulaic phrasing, contraction rate, and em dash frequency. Every signal is shown, not hidden behind a black-box number.
This is not a Claude watermark detector. Anthropic's text watermark uses a secret key with no public detector to check against — see the guide below for why. This box scores writing style only, the same feature family used by classical ML text-detection tools. Treat the result as a discussion prompt, never a verdict.
0 word(s)
Claude's Actual Text Watermark: Detection Status
The heuristic above is a style score, not Claude's cryptographic watermark. Here's the honest gap between the two.
NO PUBLIC DETECTOR EXISTS YET
Anthropic confirms Claude weaves a statistical watermark directly into generated text, but as of publication its detection tooling is “forthcoming” — no public API, threshold, or spec is available. The detection key has to stay secret for the scheme to work at all, so there is nothing a script or browser tool can check against today.
Why the heuristic above isn't that detector
Stylistic features can be edited away in a sentence; a cryptographic watermark is designed to survive that. Read the full mechanism — and what a real detection result would and wouldn't prove once Anthropic ships one — in the companion guide.
READ THE DETECTION GUIDE →Related reading