Unicode Inspector
Find the zero-width spaces, direction overrides, look-alike letters and stray control characters that make two identical-looking strings compare unequal.
Everything on this page runs in your browser. Nothing you paste is uploaded, logged, or written into the URL — only the settings are, so a configured tool can still be linked to.
4 of them are completely invisible in your editor. 71 code points across 71 UTF-16 units.
- Code points
- 71
- UTF-16 code units (JavaScript's .length)
- 71
- UTF-8 bytes
- 80
- Characters outside ASCII
- 6
- Invisible / zero-width
- 2
- Direction controls
- 2
- Spaces that are not U+0020
- 1
- Latin look-alikes
- 1
- Already in normal form C
- yes
- errorline 1, column 3 · U+200BZERO WIDTH SPACE — invisible, and the single most common cause of a string comparison that should have matched
Expected: nothing at this position, unless you put it there deliberately
This invoice is overdue.⏎Pa… - warnline 1, column 22 · U+00ADSOFT HYPHEN — invisible unless the line wraps here, and it survives copy and paste
Expected: nothing at this position, unless you put it there deliberately
This invoice is overdue.⏎Pay now at examplе.co… - warnline 2, column 4 · U+00A0NO-BREAK SPACE — looks exactly like a space and is not one; splitting on " " leaves it attached to the word
Expected: U+0020 SPACE, if this was meant to be an ordinary space
…s invoice is overdue.⏎Pay now at examplе.com⏎Amount … - warnline 2, column 18 · U+0435looks like Latin "e" and is not — renders identically to "e" in most fonts but is a different code point, so any comparison against the Latin spelling fails — and a domain or a command written this way is not the one it appears to be
Expected: the Latin letter it is imitating
…verdue.⏎Pay now at examplе.com⏎Amount due: 123 USD - errorline 3, column 13 · U+202ERIGHT-TO-LEFT OVERRIDE — invisible, and can make text display in an order completely different from the order it is stored in — the trick behind reversed filenames and the Trojan Source class of attacks
Expected: nothing at this position, unless you put it there deliberately
…t examplе.com⏎Amount due: 123 USD - warnline 3, column 17 · U+202CPOP DIRECTIONAL FORMATTING — invisible; closes a direction override
Expected: nothing at this position, unless you put it there deliberately
…amplе.com⏎Amount due: 123 USD
This invoice is overdue. Pay now at examplе.com Amount due: 123 USD
Why an invisible character is worse than a visible bug
A zero-width space between the h and the i of "this" costs nothing to produce — a word processor, a wiki, a copy out of a rendered web page — and it survives every step of a pipeline unchanged. It makes a string comparison fail, a dictionary lookup miss, a cache key differ from the key you expected, and a tokenizer split one word into two, which quietly raises the token count of every prompt built from that text. None of those failures print anything you can search for. The only reliable way to find one is to look at the code points, which is what this page does.
The two that are security problems, not tidiness problems
A right-to-left override makes stored text display in an order it is not stored in, which is how a file called gnp.exe shows up as a PNG and how a comment in source code can render as if it ended where it did not. Tag characters are worse for anything involving a language model: each one carries an ASCII letter, they are completely invisible to a human reviewer, and a model reads them as text. A document that looks harmless on screen can carry a paragraph of instructions in them. If your system ingests text that other people wrote, stripping both of those at the boundary is a one-line change with no downside worth arguing about.