Trim white margins off PDF pages

Scans and print-ready PDFs arrive with fat margins. Crop them down so the content fills the view — reversibly.

Tools used in this guide

The job

Reading a scanned letter on a phone means pinching past an inch of white border. Setting a CropBox shrinks what viewers display while leaving the underlying content untouched — the trim is reversible.

Crop it

Choose the PDF, enter the trim per side in millimetres, and optionally a page range like 1-3,5. The tool writes a new CropBox on those pages; nothing is deleted. If any page would end up under 10 pt, the run aborts with no output.

10 mm ≈ a typical loose-leaf margin.
Asymmetric trims (e.g. left 30 mm for a binding edge) work per-side.

Worked example

A receipt scanned at A4 with ~20 mm of empty border: trim 20 on all sides and the receipt fills the phone screen. The original content is still there underneath — open it in a PDF editor and reset the box if the trim went too far.

Limits

CropBox only — printers and viewers honor it, but the bytes underneath are recoverable, so do not use cropping to redact. Up to 200 pages / 25 MiB. Encrypted and signed PDFs are not supported.