Guide ·
How to redact a PDF, and check that it worked
Redacting means removing information so nobody can get it back. Drawing a black rectangle over text isn't enough: the words usually stay in the file and can be copied out from under the box. Redact PDF deletes what's under each box, then fills the area in black.
Step by step
- 01
Open Redact PDF and add your file
Drop the PDF. Its pages appear so you can mark them.
- 02
Search for names and numbers
Type a word, name or number and select Mark all to box every match in the document. Search ignores capital letters; tick Whole words only to skip matches inside longer words.
- 03
Draw boxes over everything else
Drag a box over signatures, photos, stamps or anything search can't find. Remove a box you didn't mean with its ✕ button.
- 04
Redact and download
Select Redact PDF. What's under the boxes is removed from the file, and the areas are filled in black.
What gets removed
- Text: every character a box touches is taken out of the page. The rest of the line stays as it was.
- Pictures: the pixels under a box are blacked out in the image itself, and a picture that sits entirely inside a box is deleted.
- Links, comments and form fields that a box overlaps.
- Page thumbnails stored inside the file, so they can't show the original.
What search can't find
- Scanned pages. They're pictures, so there are no words to search. Draw boxes by hand; the pixels underneath are removed.
- Text that is rotated, vertical, or part of a placed graphic such as a logo.
- The second line of a match that wraps onto the next line. Only the first line gets a box, so draw one over the rest.
- Variations. Search looks for exactly what you type, ignoring capitals, so search separately for every spelling, format and number you need to remove.
Mark all boxes every match, even when the list beside the search shows only the first 50.
Check that it worked
Before redacting is finished, PocketPDF checks every page that has a box: no text may be readable inside a box, and nothing outside the boxes may have changed. A page that fails is rebuilt as a picture of the redacted page, and if that fails too the job stops instead of giving you an unsafe file. Then check it yourself:
- Open the redacted copy and search (Ctrl+F, or ⌘F on a Mac) for each word you removed. It shouldn't be found.
- Select the text around a black box, copy it and paste it into a note. The removed words shouldn't appear.
- Look through every page, including headers, footers, stamps and photos, for anything search couldn't find.
- Check the document's properties (title, author, subject) in your PDF reader. Redaction doesn't change them.
Why a page might turn into a picture
When part of a page can't be taken apart safely, for example text inside a placed graphic, or a page fails the check, it's replaced by a 150 DPI picture of the redacted page. That page's text can no longer be selected or searched; other pages keep theirs.
Covering isn't redacting
White-out and shapes in Edit PDF only paint over the page, and the text stays underneath. Use Redact PDF whenever information has to be removed. Before you send the redacted file, you can also add a password.
Questions
- Can I use a colour other than black?
- No. Redacted areas are always filled in black.
- Can redaction be undone?
- Not in the redacted copy; that's the point. The file you uploaded isn't changed, so you can start again from it if you need to redact differently.
- Does it work on scanned documents?
- Yes, with boxes you draw: the image pixels under each box are blacked out. Search won't find words on a scan.