How to crop a PDF
- Drop one PDF into the box above.
- Keep Pages to crop as
allfor a uniform crop, or type pages such as1, 3-4. - Enter how many millimetres to trim from the top, right, bottom, and left, then press Apply crop.
- For different margins on different pages, change the pages and values and apply again. Crops add up.
- Press Save cropped PDF and open
yourfile-cropped.pdfto check the result.
How cropping works here
Every PDF page has a CropBox: the rectangle a viewer shows. This tool shrinks that rectangle with pdf-lib by your margins (1 mm ≈ 2.83 pt). If you tick Also set MediaBox, the page size itself is set to the same rectangle, which some print workflows prefer. All of it runs in this tab — no upload (see the trust check).
Honest limits — read before sharing
- Cropping is not redaction. The content outside the crop is hidden, not deleted. Anyone can reset the CropBox or extract text and images from the file. Do not use crop to hide private information.
- No visual preview. You set margins by number; open the saved file to check. Start small and apply again if needed.
- Margins follow the page’s unrotated orientation. On a page shown rotated, “top” is the top of the page before rotation.
- Same file size. Because nothing is removed, the file does not get smaller.
- Saving rewrites the PDF and invalidates digital signatures. A crop that would leave less than 10 pt is refused. Soft limit about 25 MiB; encrypted PDFs are rejected.
Related tools: rotate PDF, remove PDF pages, split PDF, and merge PDF.
FAQ
Does cropping a PDF delete the hidden content?
No. Only the visible CropBox changes. The trimmed area is still in the file and can be recovered, so cropping is not a way to remove private information.
Can I crop only some pages?
Yes. Type the pages, set margins, and apply. Repeat with other pages and values before saving.
What unit are the margins in?
Millimetres. The tool converts them to PDF points (72 per inch) and trims that much from each side of the current crop box.
Is the PDF uploaded to crop it?
No. pdf-lib changes the page boxes in this tab’s memory and the download is created locally.
What does Also set MediaBox do?
It sets the page size to the cropped rectangle as well as the visible area. The hidden content is still in the file either way.
Will cropping make my PDF smaller?
No. Nothing is removed, so the file size stays about the same.