Crop a PDFto the part that matters

What cropping a PDF really does

Cropping a PDF is not the same as cropping a photograph, and the difference matters. It sets the area a reader displays, leaving everything outside it in the file — hidden rather than removed, and recoverable by anyone who widens the box again. That is worth knowing before you crop a bank statement to hide an account number. For what cropping is actually good at — scanner shadows, oversized margins, a slide deck exported with white borders — drag a rectangle over the page and the rest is trimmed away on every page you choose.

• The area is chosen as a proportion of the page, so a document mixing portrait and landscape pages crops sensibly rather than fitting the first page and spilling off the rest.
• Cropping is relative to what is currently visible, so a document that has been cropped before crops again within what is left.
• Pages stored sideways are handled properly — the rectangle you draw is the area you get, whichever way the page is stored.
• Everything runs on your device. The page ships a Content Security Policy that blocks connections to any other origin, so a document you crop here cannot be sent anywhere.