Zero-Width Spaces in ChatGPT Text: What They Are and How to Remove Them
· 4 min read · GhostVerb team
A zero-width space is a real Unicode character (U+200B) that takes up no width at all. You can't see it, your cursor skips over it, but it's there, and it travels with the text when you copy and paste.
How they get into AI text
Invisible characters reach your clipboard in a few ways:
- From the AI output itself. In 2025, users reported that some newer ChatGPT models were producing narrow no-break spaces (U+202F) in their answers. OpenAI said this was an unintended quirk, not a watermark. Other tools and plugins have inserted zero-width characters on purpose to tag text.
- From web pages and PDFs. Sites use zero-width characters for line-breaking hints, and PDFs often carry odd spaces.
- From deliberate fingerprinting. Sequences of invisible characters can encode a hidden ID, so a leaked copy can be traced back.
Why they're a problem
- They can mark text as copied or machine-made to anyone who looks.
- Search and find-and-replace fail: "report" with a hidden character inside won't match "report".
- Word counts, spell-checkers and code can behave strangely.
- Some plagiarism and AI-checking tools flag unusual characters.
The invisible characters to look for
| Character | Code |
|---|---|
| Zero-width space | U+200B |
| Zero-width non-joiner | U+200C |
| Zero-width joiner | U+200D |
| Word joiner | U+2060 |
| Byte order mark | U+FEFF |
| Narrow no-break space | U+202F |
| No-break space | U+00A0 |
| Tag characters | U+E0000–U+E007F |
Three ways to remove them
- Free checker (easiest). Paste into the hidden character checker. It highlights every invisible and look-alike character and gives you a clean copy. It runs in your browser, so the text never leaves your device.
- Paste as plain text. Pasting into a plain-text editor like Notepad strips formatting, but not zero-width characters. They're text, not formatting. This only helps with some odd spaces.
- Find and replace with a regex. In editors that support it (VS Code, Notepad++, Google Docs with an add-on), replace
[-]with nothing, and[ ]with a normal space.
Hidden characters aren't the only watermark
Removing invisible characters is quick, but some AI watermarks, like Google's SynthID, live in the choice of words instead. Those only go away when the text is fully rewritten. GhostVerb does both: it strips the characters and rewrites every sentence in your own voice.