Key takeaways
- Drawing a black box over text is not redaction — the text often stays in the file.
- True redaction removes the content underneath, so it can't be copied or searched.
- Find & redact locates every occurrence of a word or number automatically.
- Flatten every page removes hidden text from pages without visible redactions too.
Every year, confidential information leaks because someone "blacked out" text with a rectangle in a PDF editor — and the text was still there underneath, ready to copy and paste. Proper redaction removes the information for good.
Why black boxes fail
A rectangle drawn in a typical editor is just a shape on top of the page. The original text is still in the file. Anyone can select it, copy it, search for it, or simply move the box.
How true redaction works
Real redaction removes the content under the marked area and replaces it with solid black. In Osd-Scan, redacted pages are rebuilt so that no hidden text remains in those areas.
How to redact a PDF
- Open Redact PDF and add your document.
- Drag boxes over everything you want to remove.
- Or use Find & redact: type a name, ID number or account number to mark every occurrence on all pages. Tick Whole words only if needed.
- Turn on Flatten every page for maximum safety — it also removes hidden text from pages without visible redactions.
- Download the redacted PDF.
Check the result
Open the new file and:
- Try to select text in a redacted area — nothing should be selectable.
- Search for a redacted word — no results.
- Zoom in on edges to be sure nothing peeks out.
What to redact
- National ID and passport numbers
- Bank account and card numbers
- Home addresses and phone numbers
- Names of third parties
- Salaries and amounts not relevant to the recipient
Combine with other protection
- Add a watermark showing the recipient with Watermark PDF.
- Encrypt with Protect PDF before emailing.
Redact without uploading
Uploading a document to remove sensitive information defeats the purpose. Osd-Scan redacts inside your browser — the unredacted original never leaves your device.
Frequently asked questions
Why isn't a black rectangle enough?
In many editors the rectangle is just an object on top. The original text remains and can be copied, searched or revealed by deleting the box.
How do I check that redaction worked?
Open the redacted PDF, try to select and copy the area, and search for the hidden word. Nothing should be found.
Can redaction be undone?
No. Redacted content is removed from the new file. Keep your original in a safe place.
What should I redact on an ID copy?
Whatever the recipient doesn't need — often the ID number, card number or photo, depending on the purpose.