Crop PDF
Trim margins off every page of a PDF by a measurement in millimetres. Honest about the fact that cropping hides content rather than deleting it.
Cropping hides. It does not delete.
A PDF page carries several boxes. The MediaBox is the physical page; the CropBox is the region a reader displays. Cropping sets the CropBox, and everything outside it is still in the file — it is simply not drawn.
Anyone can recover it by resetting the box, and plenty of tools do it in one click. So if you are cropping to remove something you do not want seen — a name in a margin, a header, a watermark on the edge — cropping is the wrong operation. It looks like it worked and it did not.
To genuinely remove content, the page has to be re-rendered without it, which means rasterising and losing the text layer. That is a real trade and it should be a decision rather than a surprise.
Millimetres, because the page is a physical object
PDF measures internally in points, at 72 to the inch, which is a unit almost nobody thinks in. The measurements here are millimetres and are converted for you.
The crop applies to every page equally. Pages of different sizes in one document each keep their own dimensions and lose the same amount from each edge.
A page has five boxes, not one
MediaBox is the physical sheet. CropBox is the region a reader displays, and defaults to MediaBox when absent. BleedBox, TrimBox and ArtBox exist for print production — where the sheet gets cut, where the finished piece sits, and where the meaningful artwork is.
Almost every viewer honours CropBox and ignores the rest. Almost every prepress workflow reads TrimBox and treats CropBox as decoration. So a file can look correctly cropped on screen and print at the original size, which is a genuinely confusing failure and a common one.
This tool sets CropBox, which is right for reading and sharing. If the file is going to a printer, tell them what you did, because the box they care about is a different one.
Answers
Is cropped content really gone?
No. Cropping sets a display region; everything outside it stays in the file and can be restored in one click. For genuine removal the page must be re-rendered.
Will it change the file size?
Barely. Nothing is removed, so the file stays about the same size.
Can I crop pages by different amounts?
Not here — the same margins apply to every page. Split the document first if you need different crops.