Crop PDF

Oversized margins rarely come from the author. Scanners capture the whole glass bed, so every page carries black borders or gray shadows around the real content. Fax gateways and office printers add header strips with timestamps. Presentation decks exported for projection keep acres of white space that look absurd on a phone screen. And documents assembled from mixed sources — a contract here, a scanned appendix there — end up with inconsistent page geometry that screams unprofessional.

The traditional fixes are all bad: reprinting to a new PDF bloats the file and rasterizes text, screenshotting pages destroys searchability, and server-side croppers demand uploading sensitive documents to a stranger's infrastructure. Cropping the CropBox directly avoids every one of these trade-offs — it is a metadata-level change that takes seconds and preserves everything else about the file.

Every PDF page carries several boundary boxes, and viewers display the intersection defined by the CropBox. Our tool computes a new CropBox from your margin percentages — for example, 5% on each side keeps the central 90% of the page — and writes it into each selected page object with pdf-lib, entirely in your browser. Because content streams, fonts, and images are untouched, text remains selectable, file size barely changes, and the operation is fully reversible by cropping again with zero margins.

Two caveats are worth knowing. First, rotated pages (landscape scans stored as rotated portrait) crop relative to the stored orientation, so check the preview before downloading. Second, cropping hides content rather than deleting it: the bytes outside the box remain in the file. For ordinary margin-trimming that reversibility is a feature, but if you are redacting secrets, use a true redaction workflow instead — cropping is not redaction.