The Difference Between Covering and Redacting
This is the single most important thing to understand about PDF redaction:
Covering means placing a black rectangle over text in a PDF editor. The text appears hidden on screen. But the underlying data is still in the file. Anyone can select, copy, or extract that text — the rectangle is just a visual layer on top. Dozens of high-profile security incidents have resulted from organisations thinking they redacted documents when they only covered them.
Redacting means permanently deleting the underlying data from the PDF structure. The black mark replaces the content entirely. There is nothing underneath to recover, copy, or extract.
Our [Redact PDF](/redact-pdf) tool performs true redaction. When you apply a redaction and download the file, that information is gone.
How to Redact a PDF
Open our [Redact PDF](/redact-pdf) tool
Upload your PDF
Click and drag over any text or area you want to permanently remove
Review your selections — redaction is irreversible
Click Apply Redactions
Download the redacted PDF
You can redact multiple areas across multiple pages in a single session. The tool shows a preview of the redacted areas before you apply them, so you can verify coverage.
What to Redact — A Practical Checklist
The right things to redact depend on your context, but common categories include:
Personal identifiers: Full names (when not the document subject), home addresses, phone numbers, email addresses, dates of birth, national insurance or social security numbers, passport numbers, driver's licence numbers.
Financial data: Bank account numbers, credit card numbers, sort codes, salary figures (when sharing to certain parties), tax reference numbers.
Medical information (HIPAA/GDPR): Patient names, dates of service, diagnosis codes, prescription details, insurance policy numbers.
Legal proceedings: Witness names and addresses (when protected), sealed testimony, juvenile records, details protected by court order.
Internal business data: Internal pricing, supplier contracts, staff performance data, unreleased product information.
After Redacting — Verify It Worked
Before sharing any redacted document, verify the redaction is genuine:
Open the downloaded PDF
Try to select or click on the redacted areas
If the selection tool picks up text underneath the black marks, the redaction failed — the file was covered, not redacted
Try Ctrl+F (Find) and search for a term you redacted — if it appears in search results, the text is still in the file
A correctly redacted PDF will have no selectable text in the redacted areas and will return no results when searching for redacted terms.
Protecting the Final Document
After redaction, consider adding an additional layer of security:
[Flatten the PDF](/flatten-pdf) — merges all layers so no PDF editor can separate the redaction marks from the underlying page
[Password protect](/protect-pdf) — adds encryption so only authorised recipients can open the file
Check metadata — use a PDF properties viewer to ensure document metadata (author, revision history) doesn't contain information you meant to remove
Compliance Contexts
GDPR (EU): When sharing documents containing personal data of EU citizens, redact information that recipients don't have a legitimate reason to see. This applies to HR files, customer records, contracts, and legal correspondence.
HIPAA (US healthcare): Medical records shared for insurance, legal, or research purposes must have the 18 HIPAA-defined identifiers removed before sharing outside a treatment relationship.
FOIA responses (government): Public records released under freedom of information laws must have exempt information redacted. True redaction (not covering) is required.
Legal discovery: Documents produced in litigation often require redaction of privileged information. Law firms have faced sanctions for cover-only redaction that left data accessible.
Frequently Asked Questions
Is the redacted information truly unrecoverable?
Yes, when using our tool. True redaction removes the data from the PDF file structure — not just visually hides it. The underlying bytes no longer exist in the file.
Can I redact images, not just text?
Yes. Draw your redaction box over any area — text, images, signatures, charts, photographs. The entire selected area is permanently removed and replaced with a solid mark.
What if I redact the wrong area by mistake?
Do not download — instead, remove the incorrect redaction mark before applying. Once you click Apply and download, the redaction is permanent. Always review carefully before applying.
Should I keep the original unredacted version?
Yes, always. Keep the original in a secure location. The redacted version is for sharing; the original is your record. Never replace the original with the redacted version.
Does redaction work on scanned PDFs?
For scanned PDFs, the redaction marks cover the visual area of the scan. Since scanned content is an image (not text), there's no underlying text to recover anyway. However, if you've run OCR on a scanned PDF first, redact before sharing to remove any OCR-generated text layer.