PDF Cropper trims the margins of a PDF and sets a new crop box on each page, then lets you preview the result and download a fresh file. Use it to cut the white border off a scanned document, tighten an over-padded export, fit slides onto a single printed sheet, or remove the header and footer band from a report — all without re-rendering or degrading the page content.
Every PDF page carries two rectangles that matter here: the media box, which is the page’s full physical size, and the crop box, which is the region a viewer or printer actually shows. Cropping simply sets a smaller crop box. The tool measures your trim amounts in millimetres inward from each edge, so a value of 10 on the left removes a 10 mm strip from the left side. You can edit the four edges independently or link them for a uniform margin.
How it works
When you open a PDF, the tool reads each page’s size with pdf-lib directly in the browser. As you
type margins, a live SVG preview redraws the surviving crop box over a scaled outline of the page so
you can see exactly what will be kept and what will be discarded. A page selector with a slider lets
you move through the document and inspect or override any page.
A document-wide crop can target all pages, only odd pages, only even pages, or a custom range like
1,3-5,8. For pages that need something different, the Override this page button stores a separate
crop just for that page; overrides are highlighted and tallied in the summary. On export the tool
rewrites the crop box (and, optionally, the media box for a permanent hard crop) for every affected
page and hands you a downloaded file. Pages where the crop would leave nothing are skipped rather than
emptied.
Example
Suppose you scanned a book at A4 (210 × 297 mm) but each page has a 15 mm white border and a 20 mm gutter on the binding side. Set top, bottom and outer margins to 15 mm, then use the odd/even scope to apply a 20 mm left inset on right-hand pages and a 20 mm right inset on left-hand pages. The preview confirms the text block is centred, and the exported PDF reads tightly with no wasted border.
| Page size | Top/Bottom | Left/Right | Result |
|---|---|---|---|
| A4 210×297mm | 15mm | 15mm | 180×267mm content |
| Letter 216×279mm | 0mm | 25mm | narrow column extracted |
| A4 210×297mm | 40mm | 0mm | header and footer removed |
Every figure is processed in your browser — no pages are uploaded or stored.