How to Crop PDF Pages and Trim Margins
Crop PDF pages to remove unwanted margins, white space, or areas around your document content. Cropping can give your PDF a cleaner appearance and help focus attention on the important parts of each page.
Understanding the crop box
Every PDF page has a 'crop box' — a rectangle defining what's visible. Cropping doesn't delete page content; it changes the crop box so viewers and printers only show the inner rectangle. The original content is preserved (a recipient with the right tools could enlarge the crop box back), but for practical purposes the cropped area is gone.
Setting margin values
PDFPuddle uses points for measurement. 72 points = 1 inch = approximately 25.4 mm. To trim 1 cm from each margin, enter 28 points (1 cm × 28.35 points/cm, rounded). Top, right, bottom, and left are independent — useful for asymmetric trims.
Common crop scenarios
Trim 30–50 points from each margin to tighten an ebook for tablet reading. Crop the right margin heavily (200+ points) to remove a sidebar. Crop the bottom (100+ points) to remove footer content like timestamps from automated PDFs.
Resizing pages instead
If your goal is changing page size (A4 → Letter, for example), cropping is the wrong tool — it removes content, doesn't resize. Use a desktop tool with a 'page size' setting, or convert through Word using Word to PDF with the target page size selected.