Covering text with a black box doesn't remove it — the data is still there, and anyone with basic tools can extract it. Real redaction permanently deletes the content from the file. If you're removing sensitive information, you need true redaction.
This guide explains the critical difference between redaction and covering, what you should redact, and how to do it properly.
Redaction vs. Covering: The Critical Difference
Just Covering Text (WRONG for Sensitive Data)
Drawing a black rectangle over text using annotation tools only hides it visually. The underlying text remains in the PDF and can be:
- Selected and copied
- Extracted with PDF tools
- Exposed by removing annotations
- Indexed by search engines
This is NOT secure redaction.
True Redaction (CORRECT)
Proper redaction permanently deletes the content from the file. After redaction:
- The text is gone — completely removed from the file
- Black boxes replace the deleted content
- No way to recover or extract the original text
- Even forensic analysis can't retrieve the data
What Should You Redact?
Personal Identifiable Information (PII)
- Social Security numbers
- Date of birth
- Home address
- Phone numbers
- Email addresses
Financial Information
- Bank account numbers
- Credit card numbers
- Salary and compensation
- Tax information
Medical Information
- Patient identifiers (HIPAA)
- Medical record numbers
- Diagnosis information
- Treatment details
Legal and Business
- Confidential contract terms
- Trade secrets
- Witness names
- Settlement amounts
How to Redact in PDF
- Upload: Go to our Redact PDF tool and select your document
- Mark areas: Draw boxes over content you want to permanently remove
- Review: Double-check marked areas before applying
- Apply redactions: Permanently delete the marked content
- Download: Get the redacted document — sensitive data is gone forever
Tips for Thorough Redaction
Check Hidden Data
PDFs can contain hidden data beyond visible text:
- Metadata (author name, creation date)
- Comments and annotations
- Layers and hidden text
- Previous versions (document history)
Professional redaction tools remove this too.
Be Consistent
If you redact a name on page 1, make sure you catch it everywhere else in the document.
Verify After Redaction
Open the redacted PDF and try to select text in redacted areas. If you can select anything, it wasn't properly redacted.
Combine With Other Security
- Password protect after redacting
- Add "Redacted" watermark for clarity
- Archive the redacted version
Related Tools
- Password protect PDF
- Add watermark
- Unlock PDF (before redacting)
- Edit PDF
Common Questions
Can redacted content be recovered?
No. True redaction permanently deletes the content. Unlike covering with a black box, there's nothing left to recover.
What's left after redaction?
A black rectangle where the content used to be. The original data is completely gone.
Should I redact or password protect?
Different purposes. Password protection controls who can access the document. Redaction removes specific content entirely. Often you'll want both.
Can I redact scanned documents?
Yes, but scanned documents are images. You're removing parts of the image. Running OCR first helps identify text to redact.
Protect sensitive information properly. Redact now — free and permanent.