Mask an area of a PDF (visual redaction)

⚠️ Warning, read this before using this tool: it only draws an opaque black rectangle over the specified area. The text or image located under this rectangle is not removed from the PDF file: it remains present in the underlying data stream and can be recovered by anyone who copies the "hidden" text, inspects the file with a PDF editor, or removes the black layer. Do not use this tool to mask genuinely confidential information (personal data, account numbers, secrets, etc.) without prior review by a competent person. True secure redaction must remove the text from the document, not just visually cover it.

Drag and drop a PDF file here, or click to choose50 MB max
Example:

Coordinates in PDF points (72 points = 1 inch), origin at the bottom left of the page.

How it works

For each area you define (page number, position, and size in PDF points, with the origin at the bottom left of the page), the tool adds an opaque black rectangle directly into the page's content, over everything already there. This lets you quickly mask information visible on screen or in print, without a complex PDF editor: a simple form is enough to indicate where to place the mask.

How do I find the coordinates of an area to mask?

Coordinates are expressed in PDF points (72 points = 1 inch), with an origin at the bottom left of the page (unlike a screen, where the origin is usually top left). An A4 page is about 595 x 842 points. You'll generally need to open the PDF in a viewer that shows the cursor's coordinates, or proceed by trial and error, adjusting the values until you get the desired area.

Can I trust this tool for sensitive data?

No, not in its current form: as explained above, it only masks the display, it does not remove the actual content. For truly removing sensitive data, you need a tool that actually strips the text and images from the PDF's stream (not just covers them), and ideally a manual check of the result before distribution.

As with all our PDF tools, this processing is calculated 100% locally in your browser thanks to WebAssembly: your document never leaves your device.