Claude watermark guide
AI Watermark Checker
An AI watermark checker can only make claims that match the signal it tests. This tool checks observable Unicode and supported metadata; it does not claim to detect vendor-keyed statistical watermarks.
Start with the signal
Ask whether the claimed mark is metadata, pixels, Unicode, or a token-selection watermark. Each needs different evidence.
Avoid false certainty
A result should state its scope, source data, and limits instead of assigning a vague universal score.
Check your Claude text
Inspect every detectable hidden character locally, then clean only the artifacts you select.
Check Text FreeSources
Published August 2026 · Updated September 1, 2026