Claude watermark guide
Does Claude Watermark Text?
Yes. Anthropic says newer Claude models use a statistical text watermark created through patterns in word selection. It does not consist of hidden Unicode characters or metadata appended to a response, so copying text does not inherently remove the signal.
How the text watermark works
Anthropic describes the signal as a keyed statistical pattern across word-selection choices, not an extra character or metadata field. A third party cannot independently confirm its presence or removal without the appropriate detector.
Why hidden-character checks are still useful
Copied text can still carry unrelated Unicode controls or formatting residue. Those artifacts are independently inspectable, but they are not Claude’s official watermark.
Check your Claude text
Inspect every detectable hidden character locally, then clean only the artifacts you select.
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Published August 2026 · Updated September 1, 2026