Claude watermark detector
Check text for a Claude provenance signal.
Your text
0 words3,000 words per free check
About this check
Current state
Anthropic has not published a text watermark or a way to verify one. The Claude provenance check therefore reports 'Not verifiable' — the adapter exists so the check can be switched on without any other change, the moment a method is published.
What still gets checked
The invisible-character analysis runs on every text check. If the text passed through a tool that embedded markers, they show up regardless of which model produced the words.
If you need certainty
For a text with no embedded marker, no tool can give it. The reliable paths are procedural rather than technical: version history, drafts, and disclosure. A provenance checker tells you what is in the file — not who typed it.