Crop PDF Margins

1. 1Add the PDF — the first page is shown with a dashed outline over it.
2. 2Drag the margin slider, or untick the box to set each side separately.
3. 3Watch the outline: everything inside it is kept.
4. 4Press Crop margins and download the trimmed file.

Cropping a PDF does not delete anything. Every page carries two rectangles: the media box, which is the paper, and the crop box, which is the part a viewer actually shows. This tool sets the crop box, which is how professional tools crop and how every reader and printer expects a crop to be expressed.

Because the content is untouched, text stays sharp and selectable, the file size barely changes, and the crop can be undone by anyone who wants the full page back. On an e-reader the effect is dramatic: removing a 20 mm border from an A4 page makes the text roughly a third larger on the same screen.

Margins are entered in millimetres and converted to PDF points at 72 points per inch. Each page is measured from its own media box, so a document with mixed page sizes crops consistently rather than by a fixed number of pixels.

The file is read into your browser's memory, changed there, and handed straight back to you. Nothing is uploaded, so there is no queue and no copy sitting on a server afterwards.

• Crop academic papers before reading them on a tablet or e-reader — removing a wide border makes the text noticeably larger on the same screen.
• Watch the dashed outline on the first page; everything inside it is kept.
• Untick the equal-margins box when a document has a wider binding margin on one side.
• Cropping hides content rather than deleting it. To remove something for good, use Redact PDF.

• How to read PDFs comfortably on a tablet, phone or e-reader
• How to read a PDF in dark mode
• Why a PDF prints too small or gets cut off, and how to fix it