How to Redact a PDF Properly — Black Boxes Are Not Enough
September 20, 2026 · 5 min read
Governments, law firms and banks have all made the same mistake in public: they drew black rectangles over sensitive text in a PDF, published it, and someone selected the text underneath and pasted it into a notepad. The names were still there the whole time.
It happens because a PDF page has two separate things going on. There is what the page looks like, and there is the text stored in the file. A black rectangle only changes the first one.
Three ways people "redact", and what actually happens
| Method | Is the text gone? |
|---|---|
| Black rectangle drawn on top | No — copy and paste retrieves it |
| Highlighter set to black | No — it's an annotation, removable in one click |
| Print to PDF after covering | Usually yes, but the whole document becomes a flat image and stops being searchable |
| True redaction | Yes — the characters are deleted from the file itself |
How to redact a PDF for real
- Open RizzPDF Redact PDF
- Upload the document
- Drag a box over anything sensitive, or search for it — you can also match every email address, phone number or ID at once
- Check the list of what will be removed
- Download. The boxes are drawn and the underlying characters are deleted
Afterwards, prove it to yourself: open the redacted file, try to select the blacked-out area, and search for a word you removed. Nothing should come back.
The parts people forget to check
- Metadata. Author, title and the original filename often name the person the document is about.
- The file name itself. "Smith_termination_final.pdf" defeats an afternoon of careful redaction.
- Attachments and comments. Sticky notes and reviewer comments travel with the file — flattening deals with those.
- Copies of the same data elsewhere in the document — a total in a table, a name repeated in a footer.
- Small images. A signature, a logo or a screenshot can identify someone as surely as text.
Why an offline tool is the right choice here
Redaction exists because a document contains something that must not spread. Uploading that document to a stranger's server to remove the secret is a strange way to keep it. RizzPDF works inside your browser: the file is never transmitted, so the unredacted version only ever exists on your own machine.
Is it free?
Yes — unlimited, no account, no watermark, no page limit. Redaction is exactly the kind of thing people need once, urgently, and shouldn't have to buy a subscription to do safely.
One caution
Redaction can't be undone, and it shouldn't be — that's the point. Keep the original somewhere safe before you redact, and always review the finished file before sending it on.
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