Invisible characters in text: what they are and how to remove them
Text can carry characters you'll never see. They render as nothing — no width, no mark — yet they sit right there in the file, between the letters you can read. They're used to watermark a document, fingerprint who a leaked copy came from, or spoof a word so it looks normal but isn't.
The three kinds worth knowing
- Zero-width characters — like the zero-width space (
U+200B). Invisible spacers that can encode a hidden message by their pattern. - Unicode "tag" & variation-selector characters — a modern trick for smuggling an entire hidden string inside ordinary-looking text.
- Look-alike letters (homoglyphs) — a Cyrillic
аor Greekοstanding in for the Latin letters they resemble. The word looks right; the letters aren't.
Where they come from
They turn up in text copied from documents, generated by tools, or pasted from the web. Sometimes they're harmless leftovers; sometimes they're a deliberate marker so a document can be traced back to you. Either way, if you're pasting text into something public, you probably don't want to carry an invisible fingerprint along.
How to detect and remove them
You can't eyeball this — the whole point is that it's invisible. You need a tool that inspects the actual character codes. scrub does exactly that, on your own device:
- Drop in a text or code filescrub reads the real characters, not just what's on screen.
- See what's hiddenIt lists zero-width characters, tag characters, look-alike letters and unusual whitespace — with a count of each.
- Clean itOne click strips the hidden characters and normalises look-alikes back to plain letters, leaving your real content intact — then re-checks to confirm they're gone.
Ahead of the next trick
New hiding techniques appear all the time, so scrub doesn't only match a fixed list. It also flags anomalies — characters from unusual Unicode categories, words that mix scripts, and the regular "rhythm" that gives away an encoded watermark — so something invented tomorrow still trips a warning today.
Paste with confidence. Get scrub free and clean a file in seconds.