Provenance Lens

Does Claude Watermark Text?

Anthropic documents statistical marking for newer Claude models, but no public detector. Learn what the mark would mean and what remains uncheckable.

Updated: Published by Provenance Lens

Current answer

Anthropic says newer Claude models mark generated text statistically. No public detection mechanism is available, so Provenance Lens reports this check as UNSUPPORTED.

What a future match would mean

Anthropic describes the mark as evidence that Claude processed text, not proof that Claude authored every word. Editing and paraphrasing can also affect the signal.

What a report cannot prove

  • A valid signature proves who signed a manifest, not that the manifest's claims are true.
  • Metadata is trivially editable. Treat generator fields as an indication, never as proof.
  • Hidden Unicode characters have many innocent causes, including ordinary copy-paste.

Primary sources