PDF Redaction Tool

About this tool

Permanently blacks out sensitive parts of a PDF — an account number, a signature, a name — by drawing redaction boxes directly on each page, then flattening the whole document into images before saving. Unlike drawing a black box that merely sits on top of the original text (which anyone can select, copy, or delete to reveal what's underneath — a surprisingly common real-world redaction failure), this rebuilds the PDF from rasterized page images, so there's no selectable or extractable text left underneath a redaction at all.

Everything runs locally in your browser using pdf.js (to render pages) and pdf-lib (to rebuild the PDF) — your file is never uploaded anywhere.

Frequently asked questions

Why does the whole document become images, not just the redacted areas?

Flattening every page uniformly is what guarantees no original text survives anywhere to be selected or extracted — redacting only the boxed areas while leaving the rest as real text would still be secure for what's covered, but mixing rasterized and vector content on the same page adds real complexity for no real security benefit, so this tool keeps it simple and uniformly safe.

Does this reduce text searchability in the output PDF?

Yes — since every page becomes a flat image, none of the text (redacted or not) remains selectable, searchable, or copyable in the output file. If you need to keep the rest of the document searchable, this tool isn't the right fit — it's built specifically for the case where flattening everything for security is the point.

Can I undo a box after drawing it?

Yes — "Undo last box" removes the most recently drawn box on the page you're currently viewing. Nothing is permanent until you click "Apply redactions & download".

Is my PDF uploaded anywhere?

No — rendering, redacting, and rebuilding the PDF all happen entirely in your browser. Nothing is sent to any server.