Quick answer
To redact a PDF properly, use a redaction tool that deletes the underlying text and images, not one that just draws a black box on top. Mark the areas, apply the redactions, strip hidden metadata, then check the result by trying to select or search the redacted text. If you can still copy it, it wasn't redacted.
Why aren't black boxes enough?
A PDF is made of layers. If you draw a black rectangle over a name, the name is still in the file underneath. Anyone can often select the text, copy it, or remove the box. This mistake has exposed confidential information in court filings and government documents.
Real redaction deletes the content under the marked area and replaces it with a solid box, so there is nothing left to recover.
How do I redact a PDF step by step?
- Open Redact PDF and drop in your file.
- Choose Redact area and click over each piece of sensitive information.
- Optional: type a word or number into Find & redact text to catch every occurrence.
- Keep Also strip hidden metadata turned on.
- Click Apply redactions and download.
How can I check the redaction worked?
- Open the redacted PDF and try to select text in the blacked-out area.
- Use Find (Ctrl+F) to search for a redacted word.
- Or run the file through the Redaction checker, which flags text still hiding under boxes.
What should I redact?
| Information | Example |
|---|---|
| Identity numbers | Aadhaar, PAN, passport, SSN |
| Financial details | Account and card numbers |
| Contact details | Phone numbers, emails, addresses |
| Hidden data | Author name, comments, document history |
Auto-redact PII can find emails, phone numbers and ID numbers for you. Always review what it found before applying.
Frequently asked questions
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