UtilityBaseText Tools
Invisible Character Detector
Find zero-width spaces, curly quotes, and other hidden characters breaking your text.
Updated July 7, 2026
How to use the invisible character detector
- 1Paste the misbehaving text — code, a string that won't match, a filename.
- 2Review the findings: each hidden character with its code point, name, and positions.
- 3Click clean to normalize, then copy the result back.
- 4If it reports clean, your bug is elsewhere — at least this is ruled out in seconds.
Common uses
- Fixing code that fails to compile after being copied from a website or chat
- Debugging string comparisons that fail on visually identical text
- Removing a BOM that's breaking a script or config file
- Straightening curly quotes before running pasted commands
Frequently asked questions
Why does my copied code refuse to run when it looks identical?
Almost always a non-breaking space (U+00A0) or zero-width space (U+200B) that arrived with the copy — websites and chat apps insert them freely. Compilers and interpreters see a different character than a space, and the error messages rarely say so. Paste the code here and the culprit lights up with its exact position.
Where do these characters come from?
Word processors auto-substitute curly quotes and em dashes; websites use non-breaking spaces for layout; some platforms inject zero-width characters as tracking watermarks; and copy-pasting across apps preserves all of it invisibly.
What exactly does the clean button change?
Exotic spaces of every width become regular spaces, zero-width characters and directional marks are removed entirely, and curly single/double quotes straighten to ' and ". Visible text is otherwise untouched.
Are zero-width characters ever legitimate?
Yes — zero-width joiners build multi-part emoji, and directional marks matter in mixed Hebrew/Arabic text. In source code and identifiers, though, they're virtually always accidental and worth removing.
About this tool
The invisible character detector scans text for the hidden characters that cause maddening, invisible failures: zero-width spaces that break string comparisons, non-breaking spaces that crash compilers, BOMs at the start of files, directional marks, exotic Unicode spaces, and the curly quotes that word processors substitute into code. Each finding shows its Unicode code point, name, count, and positions. One click normalizes everything — space-like characters become regular spaces, zero-width characters are removed, curly quotes straighten — turning 'this code looks identical but won't run' into a solved problem. The usual crime scene: code copied from a website, a chat app, or a Word document.
Like everything on UtilityBase, the invisible character detector runs entirely in your browser — nothing you enter is uploaded or stored on a server. It's free to use with no account required. Browse more text tools here.
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