What is Hidden Character Detector?

Some characters are invisible and still break everything: a zero-width space pasted from a rich-text editor makes a string comparison fail even though two values look identical, and directional override characters copied from a chat message can silently reverse the display of the text after them. This detector scans your text for characters you cannot see but parsers can.

It reports each finding by category — zero-width characters (space, joiner and non-joiner), invisible formatting marks, and the bidirectional overrides used in right-to-left text attacks — with the position of every occurrence and its Unicode code point, so you can locate and delete them in your editor. When nothing is hidden, it says so plainly, which is just as valuable: strings that look suspicious but are clean, confirmed.

The practical scenarios: a login check that fails against identical-looking credentials, a database join that misses rows, a code review where a copy-pasted constant misbehaves, and the security review of any text that will be displayed to users — hidden RTL characters are a known spoofing technique for file names, usernames and links.

The scan runs locally in your browser; the text is analyzed in your tab and never uploaded. Paste, review the summary, and clean the input where the positions point.