badloHow to Redact a PDF Properly
Updated
If you draw a black shape over a name in a PDF, it may look hidden, but the words are often still in the file. Anyone can copy them out or search for them. Redaction removes them.
Test it yourself
In a document covered with drawn boxes, try selecting the text under a box, and paste it somewhere. Or search for a hidden word. If you get a result, the word is still there. Highlighting text in black has the same problem.
How to redact
- Open Redact PDF and upload your document.
- Type words that appear several times, such as a name, with commas between them.
- Drag boxes over anything else, including signatures and photos.
- Download the new file. Your original isn't changed.
Check the finished file
- Search it for each removed word. There should be no results.
- Try selecting around the black areas, and paste what you get.
- Look through every page, including headers and footers.
- Look for other spellings, such as Muhammad and Mohammad.
Scanned documents
Word search can't find text in a picture, so draw boxes by hand on scans. The picture underneath is removed where each box sits. Not sure what kind of PDF you have? Read scanned vs digital PDFs.
Other ways information can leak
| Method | Is it safe? |
|---|---|
| Crop PDF | No. The trimmed area may stay in the file |
| A watermark on top | No. It only covers the page |
| Protect PDF | It locks the whole file, but anyone with the password sees everything |
| Redact PDF | Yes, for what you mark. Always check the result |
