For teachers

Audit a submission for hidden text

Paste a student's submitted work and reveal the invisible characters, white-text, and hidden content that don't show up on screen — so you can see exactly what's really there.

🔒 100% private — in-browser 🔍 reveals — position + type free — no sign-up
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Ready to audit Paste the submission on the left, then hit Audit. We'll reveal any hidden characters and text with exact positions.

What it reveals

  • Invisible characters — zero-width spaces, joiners, BOMs, soft hyphens — with their exact position and Unicode code point.
  • Hidden text — white-on-white, zero-opacity, off-screen and other hidden-HTML signals.
  • Prompt-injection patterns — instructions hidden inside pasted content.

Why audit?

Invisible characters don't show on screen, but they occupy bytes and can carry hidden markers or hidden instructions. Auditing a submission shows you what's actually there — transparently and deterministically.

This tool reveals hidden content for verification. It does not attempt to detect AI authorship — that's unreliable. For students who want to clean their own work before submitting, use the file cleaner.