Redact a PDF — black out text and images so they are really removed

How to use the PDF redaction tool

1. Drop a PDF onto the box or press Choose a file. Page 1 appears.
2. Press and drag on the page to draw a black box over the content to remove. Or press + Add box to place a box in the middle of the page and move it into place.
3. Drag a box to move it and drag its round handle to resize it. With a box selected, the arrow keys move it, Alt + arrows resize it and Delete removes it.
4. Go to other pages with ‹ and › or the page box, and add boxes there. The list under the page shows every box, with Show to jump to it and ✕ to remove it. Undo removes the last box.
5. Press Apply redaction and download the file, named with -redacted added.

What it does and when to use it

Redaction is for sharing a document while keeping some of it private: an account number on a statement, a home address in a court bundle, patient details, or a signature you do not want copied. Covering such details with a black shape in an ordinary editor is a well-known mistake, because the hidden text can still be copied out. This tool removes it.

If a whole page should go, delete it with the PDF page deleter instead. If you only want to hide margins for looks, the PDF cropper does that, but cropped content is still inside the file.

How it works

Your boxes are stored as fractions of the page, so they stay in place at any zoom. When you apply, a background worker in your browser does this for each page:

• Pages without boxes are copied unchanged with pdf-lib (@cantoo/pdf-lib).
• Pages with boxes are drawn by pdf.js (pdfjs-dist) to an image at 200 DPI. The boxes are filled with solid black on that image, with a one-pixel extra edge, and the image is saved as PNG. A new page of the original size is made that holds only this picture.

The result is a new PDF made from those pages. The covered text, the hidden text layer and any images under the boxes are not in it. Nothing is uploaded; pdf.js may download standard font or character-map data from cdn.jsdelivr.net if the PDF needs it.

Worked examples

A bank statement for a rental application. On page 1 you draw a box over the account number and another over the card number. On page 3 you cover a transaction description. The summary reads 3 areas redacted on pages 1, 3. In the saved file, pages 1 and 3 are images with black bars, and page 2 still has selectable text.

Limits and tips

• Redacted pages lose selectable text, links and form fields, and can be larger in file size because they are images. Use the PDF compressor if the result is too big.
• Comments on redacted pages and the file’s bookmarks are not carried over.
• Always open the result and try to select text under each black box before you send it.