Lookalike letters
CYRILLIC SMALL LETTER O (U+043E)
The Cyrillic letter o, drawn identically to Latin o in every font in common use.
- Codepoint
U+043E- Category
- Lookalike letters
- Removed by default
- No
- Governing option
- Lookalike letters
--confusables - Can be load-bearing
- No
Where it comes from
Cyrillic text, mixed-layout typing, and deliberate substitution in domain names, usernames and filter evasion.
Why it matters
The letter o is common enough that swapping one is nearly free: most words offer a target, and the substitution is invisible.
Before and after
The first o is Cyrillic. Nothing on screen says so.
The character is shown as a labelled chip so you can see where it sits. In your text it draws nothing at all.
When it is legitimate
In every language written in Cyrillic — Russian, Ukrainian, Bulgarian, Serbian, Macedonian and dozens more.
How to remove it
Turn on Lookalike letters (`--confusables`); it becomes Latin "o". The option destroys genuine Cyrillic, so use it only on text meant to be Latin.
Is it an AI watermark?
Not a watermark
No. Homoglyph substitution is a human technique. It is not something a language model does to its own output.
No connection to machine-generated text. It comes from software, from a keyboard, or from a person.
Questions
How can I spot one without a tool?
You cannot, reliably. In most fonts the two letters are the same shape. Searching for the Latin word will fail, which is often the first clue.
Is Greek omicron the same problem?
Yes — U+03BF is also drawn as an o. The confusables table covers Greek, Armenian, Cherokee and more, all generated from Unicode’s own confusables data.
Check your own text
Paste anything into the cleaner to see every hidden character it contains, with position, codepoint and what happens to each one. Nothing is uploaded.