How to remove margins from a PDF
Trim the white space around your pages, either by exact measurements or by letting the content decide.
Scanned books and badly configured printers both produce the same annoyance: a page where the text occupies a small island in the middle of a large white field. On a desktop monitor you barely notice. On a phone or an e-reader, that margin is the difference between readable and useless, because the reader scales the whole page — margin included — to fit the screen.
Cropping fixes this by changing which part of the page a reader displays. It is worth understanding what that means before you start: the content outside the crop is hidden, not deleted.
The steps
- Upload your PDF.
- Choose manual margins to trim a set number of points from each edge, or auto-detect to find the content on each page.
- In auto mode, set how much breathing room to keep around the detected content.
- Run the tool and download the cropped document.
Manual margins or automatic detection?
Manual mode trims a fixed number of points from each edge — 72 points to the inch. Because every page loses exactly the same amount, all your pages keep identical dimensions. That matters if the document will be printed or bound.
Automatic mode measures the bounding box of everything drawn on each page and crops to it, plus whatever padding you specify. It handles documents where the content sits in a different place on every page, which is typical of scans. The trade-off is that pages end up different sizes, because a page with a single paragraph crops much tighter than a full one.
Cropping hides, it does not delete
A crop sets the page's visible box. The text and images outside that box are still in the file, and anyone can restore them by changing the crop back. If your reason for cropping is that something in the margin should not be seen — a name, a letterhead, a stamp — cropping is the wrong tool. Redact Text removes the underlying content permanently.
A practical order of operations
If you are preparing a scan for reading on a small screen, crop first and compress second. Cropping does not reduce file size much on its own, because the hidden content is still stored, but compressing afterwards re-encodes the images and does produce a meaningfully smaller file.
