What Is a Zero-Width Space (and Why Is It in My Text)?
You paste some text and it looks completely normal. Then a tool flags it as containing an "invisible character," or spellcheck underlines a word for no visible reason, or a word count comes out one higher than it should. There's a real character sitting in the text — it's called a zero-width space, and its official code point is U+200B.
What it actually is
A zero-width space is a valid Unicode character that behaves like a space for line-breaking purposes but has no width — it renders as nothing, no gap, no mark. You can't see it, but it's there in the underlying text, sitting between two letters or words, exactly like any other character in the file.
It's not a bug or a rendering glitch. It's a deliberate part of the Unicode standard, originally meant for text layout in languages without spaces between words. But that same invisibility makes it useful for other things — some helpful, some not.
How it ends up in your text
- Copy-pasting from AI tools or web pages — some sites and generators insert zero-width characters into their output, sometimes as a byproduct of formatting, sometimes deliberately.
- Word processors and CMS editors — auto-formatting and word-wrap fixes can quietly leave one behind.
- Tracking links and fingerprinted text — the pattern of zero-width characters inserted into a document can encode a hidden identifier, so a leaked copy can be traced back to whoever it was sent to.
- Deliberate watermarking — some AI writing tools use zero-width and similar invisible characters as part of a lightweight, easily-stripped watermark.
Why it's worth checking for
Most of the time a stray zero-width space is harmless clutter — but it can also break things you don't expect: search that should match doesn't, string comparisons silently fail, code that pastes cleanly still won't compile, and a fingerprinted document can reveal exactly who a copy came from. Since it's invisible, you can't catch it by reading the text — you need something that looks at the actual characters, not just what's rendered on screen.
How to find and remove one
scrub reads the real character codes in a text or code file, on your own device — nothing is uploaded anywhere:
- Drop in the text or filescrub reads it locally and looks at every character code, not just what's visible.
- See what's hidingIt lists zero-width characters, Unicode tag characters, and look-alike letters, with a count of each.
- Clean itOne click strips the invisible characters, leaving your visible text exactly as it reads — then re-checks to confirm they're really gone.
This is the same fragile-watermark category scrub handles well — a single zero-width character or tag-character pattern is easy to strip cleanly, unlike a statistical text watermark, which survives unless you rewrite the words themselves.
The short version
A zero-width space isn't a glitch — it's a real, invisible character that can hide in pasted text for perfectly boring reasons or for tracking. You can't see it, but a tool that reads character codes can. Get scrub free and check a piece of text in seconds. For the rest of the invisible-character family, see our guide to invisible characters in text.