How to Redact a PDF Properly (Free)

To redact a PDF, open Redact PDF, mark the information to remove — search for a name or number to mark every occurrence at once, or drag boxes over areas — then click Apply redaction and download the result. Each redacted page is rebuilt with the black boxes burned in, so the text underneath no longer exists in the file. That's the difference between real redaction and simply drawing a black rectangle.

How to redact a PDF

1. Open Redact PDF and add the document.
2. Search and mark: type a name, email address, account number or phone number in the search box and click Mark all. Every occurrence on every page gets a box.
3. Draw boxes: drag on the page to cover anything else — a signature, a photo, a stamp, a table row. Use Undo to remove the last box, or click a box to delete it.
4. Choose the Quality for redacted pages: 200 dpi is a good default; 300 dpi for small print.
5. Click Apply redaction, check the result, and download it.

The redacted file is saved with "-redacted" in its name. Keep your original somewhere safe.

What happens to redacted pages

Pages with at least one box are rebuilt as flat images at the quality you chose, with the boxes part of the picture. The original text of those pages is gone: it can't be selected, copied, searched or recovered by removing the boxes. Pages without boxes are kept exactly as they were, with selectable text.

The document's properties — author, title and similar hidden details — are cleared too, because they often contain names.

A redaction checklist

Things people forget to redact:

• Every occurrence, not just the first. Searching marks them all; check the count.
• Variants: "J. Smith", "John Smith", "Smith's", initials, email addresses, usernames.
• Numbers in different formats: an account written as 12345678 in one place and 1234 5678 in another.
• Headers and footers that repeat names or reference numbers on every page.
• Signatures, photos and handwriting, which search can't find — draw boxes over them.
• Hidden properties: the redaction clears them on the output, but you can check with the PDF Metadata Editor.

Check before you share

After downloading, open the redacted file and:

1. Search (Ctrl+F or Cmd+F) for each redacted name and number — nothing should be found on redacted pages.
2. Try to select text under a black box — you shouldn't be able to.
3. Read each redacted page once more for anything you missed.

When to remove pages instead

If a whole page is sensitive — an annex with salaries, a page of medical history — it's cleaner to delete it with Remove PDF Pages than to black out everything on it. Recipients see fewer black pages, and the file is smaller.

Redaction versus passwords

Redaction removes information so that the person you send it to can't see it. A password, added with Protect PDF, stops anyone else from opening the file. For sensitive sharing you often want both: redact what the recipient shouldn't see, then protect the file in transit.

Why black boxes in other tools fail

Many redaction disasters come from drawing black rectangles in a PDF editor or in Word: the text underneath stays in the file and can be copied straight out. There's a full explanation in why black boxes don't redact a PDF.

Frequently asked questions

Is the document uploaded?

No. Redaction happens in your browser, which is exactly what you want for documents sensitive enough to redact.

Can I redact scanned PDFs?

Yes — draw boxes over the areas. Search only finds real text, so on scans you mark things by hand.

Why is the redacted file bigger?

Redacted pages become images. To shrink the file, run it through Compress PDF, or choose 150 dpi for documents with large print.