What cropping changes
PDF pages can define several boxes. Reducing the crop box changes the area normally shown by a viewer but does not guarantee deletion of objects outside it.
It can hide black borders, shadows or excess white space. File size does not necessarily shrink: images and other resources can remain embedded.
Cropping does not remove sensitive information
Do not use it to hide names, identification numbers, signatures or amounts. Another program may display a larger area or extract retained objects.
Removing sensitive data requires redaction that truly deletes contents and subsequent verification. This tool does not perform that operation.
Choose measurements and pages
Start with 3 to 5 mm and check headings, footers, signatures and codes. Four edges are independent; their names follow visible orientation, including rotated pages.
For mixed documents, work in groups. A safe crop for one sheet may hide information on a different cover or appendix.
- Correct orientation before cropping.
- Select pages or leave the field blank for all.
- Enter millimeters for top, right, bottom and left.
- Create a copy and check several sheets in another viewer.
Limits and returning to the original
Values range from 0 to 100 mm with up to 500 pages, preserving a minimum visible area. At least one edge must change. Cropping does not clean marks inside the retained area.
Keep the original instead of relying on recovering hidden contents later. For note space, use Add margins, which creates larger sheets; it is a different operation.