Hidden character detector
Paste text to reveal invisible characters and look-alike letters that can be used to trace who shared it.
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- Invisible characters
- Characters with no width: the usual way to hide a mark inside text
- Direction marks
- Marks that change the direction of text, also used to disguise file names and links
- Hidden tag characters
- Invisible characters that can carry a whole hidden message
- Soft hyphens
- Hyphens that only appear at a line break
- Unusual spaces
- Spaces of a different width from the ordinary one; a pattern of them can identify a copy
- Spaces at line ends
- Spaces or tabs at the end of lines, which nobody sees
- Look-alike letters
- Words that mix alphabets, such as a Cyrillic “а” in an English word. They are not changed in the clean text: check them yourself
Only the first 2,000 places are shown below. The count and the clean text cover the whole text.
Runs in your browser. Nothing is sent or saved.
Good to know
A document can be marked so that every copy is slightly different: an invisible character here, a wider space there, a letter swapped for its twin from another alphabet. If the text leaks, the pattern shows whose copy it was.
The clean text has invisible characters removed and unusual spaces replaced with ordinary ones. Marks made with wording, such as a changed word or comma, can't be detected by any tool: for something sensitive, retell it in your own words.
The text stays in your browser. It is not sent or saved.
A word about AI
Invisible characters matter for AI in two ways. First, a text can carry hidden instructions that you can't see but an AI assistant will read. If you paste such a text, or let an assistant read a web page or an email that contains it, the assistant may follow those instructions instead of yours. The “hidden tag characters” above are the usual carrier. Check text from a source you don't trust before you give it to an assistant.
Second, text written by AI tools sometimes arrives with unusual spaces or invisible characters of its own. Not every such character is a deliberate mark, but the clean text removes them either way. Watermarks that work through the choice of words, which some companies are developing, can't be seen or removed by this tool.