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Auto-Crop PDF (Remove Margins) Online Free — PrivaTools

TL;DR: Upload a scanned PDF and download a copy with whitespace margins auto-detected and cropped — content bounding boxes computed per page.

Auto-crop PDF online for free — automatically detect the content bounding box on every page and trim the surrounding whitespace. Ideal for reading PDFs on e-readers, tablets, or phones where screen space is limited. Also called Remove Margins. Free tool, no sign-up.

Auto-Crop PDF (Remove Margins) is one of 179+ free file utilities on PrivaTools. The entire stack is open source under the MIT license, so the privacy guarantees can be audited end-to-end. You can also run all 179 tools on your own infrastructure with one docker compose command.

How to Auto-Crop PDF (Remove Margins) with PrivaTools

  1. Upload the PDF — Drop a PDF up to 500 MB. Best for scanned documents with consistent margins.
  2. Let auto-detection scan — PrivaTools analyses the bounding box of actual content on each page using PyMuPDF — ignoring whitespace, page numbers in margins, and scan-edge artifacts.
  3. Download the cropped PDF — Click Auto Crop. Each page's MediaBox is shrunk to the detected content bounding box, eliminating dead margins.

Frequently Asked Questions

Will this make text run off the page?

No — the algorithm leaves a small safety margin around detected content. If a page has no content (blank), the original MediaBox is kept.

What if my PDF has different page sizes after scanning?

Auto-crop computes the bounding box per-page, so pages are independently cropped to their own content.

Will this affect printing?

After auto-crop, printing produces a smaller paper size. If you need the same paper size with less margin, use the Resize tool afterwards.

Last reviewed 2026-05-01 by the PrivaTools maintainers. Source code on (MIT-licensed, self-hostable).

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