How to use
- Paste the suspicious text into the left box.
- Read the summary and the inline ‹U+…› markers showing where each hidden character sits.
- Turn on “Remove the hidden characters” to copy a cleaned version instead.
About this tool
Paste text and see the characters your eyes can’t — zero-width spaces, bidirectional overrides, and invisible Unicode “tag” characters that can smuggle hidden instructions past a reader but not past a machine. Reveal exactly what’s there, or strip it out to get clean text back. Free online text tools. Everything runs in your browser — your text never leaves your device.
FAQ
Does this detect prompt injection?
It detects the mechanical part — invisible and obfuscated characters often used to smuggle hidden instructions into text an AI will read. It does not judge whether visible, ordinary-looking instructions are malicious; no in-browser tool can reliably do that, so treat a clean result as “no hidden characters”, not “safe to trust”.
Which characters count as “hidden”?
Zero-width spaces and joiners, the byte-order mark, soft hyphens, word joiners, bidirectional overrides (the “Trojan Source” family), and the invisible Unicode Tags block. Ordinary spaces, tabs, line breaks, and non-breaking spaces are left alone because they are legitimate.
What are homoglyphs, and why are they off by default?
They’re letters from other alphabets that look identical to Latin ones — a Cyrillic “а” instead of an “a”. They can be used to disguise words, but they also appear in legitimate multilingual text, so flagging them is a heuristic you opt into.
Is my text uploaded anywhere?
No. The scan runs entirely in your browser, so text you paste — including anything sensitive — never leaves your device.