How to redact a PDF properly

Sending a contract, statement or decision and want to hide an ID number, address or account number? Covering it isn't enough.

Why a black box doesn't help

When you draw a black rectangle over text in Word or a PDF reader, the text still exists underneath. Selecting and copying it — or opening the file in another program — reveals it again.

How LokalPDF does it

  1. Open the Redact PDF tool and choose the PDF.
  2. Type what you're looking for (e.g. an ID number) and click "Find and mark", or drag with the mouse over part of the page.
  3. Click "Redact and save". Pages with marks are re-rendered as an image with the black areas burned in — the original text no longer exists in the file.
  4. Check: open the result and try to select the text under the black area — it's gone.

The "Remove metadata" option also deletes the author name, title and the software that created the document — they can reveal more than you think.

Guides

How to merge PDF files on your phone You don't need a special app or an account. All you need is the browser you already have — Safari on iPhone or Chrome on Android. How to make a PDF smaller for email Gmail allows attachments up to 25 MB, and many business mail servers and portals only 5–10 MB. Here's how to make your PDF fit and still look good. How to sign a PDF without printing it Print, sign, scan, send — that loop is no longer needed for most everyday documents. How to make a scanned PDF searchable To a computer, a scanned document is just a picture: it can't be searched, copied or read aloud. OCR fixes that.