Claude watermark guide
Claude Watermark vs AI Detector
A Claude watermark detector tests a vendor-keyed statistical signal. A generic AI detector estimates writing patterns without Anthropic’s key. They answer different questions and neither should be confused with hidden-Unicode inspection.
Different evidence
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.
Practical implication
A generic detector score cannot confirm or refute Claude’s keyed watermark. State that limitation plainly.
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