How to Crop a PDF

Cropping changes the visible area of a page. It is the fix for scanner shadows, oversized margins and pages that carry a strip of the next document down one side — and you can crop a PDF page free in the browser, with nothing uploaded.

How to crop a PDF page

To crop a PDF, open it in a crop tool, enter how much to trim from the top, bottom, left and right edges, apply, and download. The trimmed margins disappear from view on every page, while the content you kept stays exactly as sharp as it was — nothing is re-rendered.

1. 1Open the Crop PDF tool and add your document.
2. 2Enter how much to trim from each edge — top, bottom, left and right — in points (72 points to the inch).
3. 3Run the crop. The same margins are trimmed from every page, and rotated pages are trimmed from the edges you actually see.
4. 4Check the result, then download.

Working out the margins in points

PDF measures pages in points, so a crop is easiest to get right first time if you convert from the ruler you are used to:

For scale, an A4 page is about 595 × 842 points and US Letter is 612 × 792. Start with a conservative trim, look at the result, and increase it — taking off too little costs one more run, taking off too much cuts into the text.

What cropping actually does

A PDF page has several boxes that describe its size. Cropping shrinks those boxes to the region you keep, which is what readers display and printers print. The content outside it is still in the file, untouched — resetting the page boxes reveals it again.

When cropping is the right tool

• Removing the black or grey border a scanner adds around a page.
• Trimming excessive white margins so a document reads better on a phone.
• Cutting away the sidebar, header or footer of a web page that was saved to PDF.
• Removing a strip of an adjacent page captured in a book scan.
• Standardising a batch of scans to one consistent visible size.

Typed pages, scans and full-page photos all crop the same way, because the crop works on the page rather than on what is printed on it.

Cropping for phone reading

A4 pages with generous margins are unpleasant on a phone, because the text column ends up small. Cropping the margins away can increase the effective text size by a third without changing the document at all — one of the more satisfying small improvements you can make to a document you have to read on the move.

Pages that are not all the same

One set of margins is applied to every page, which is exactly right for a scan where every page carries the same border — each page ends up with identical edges. A mixed document is different: a landscape chart among portrait text, or a scan where the paper moved, will be over-cropped on some pages and under-cropped on others.

The clean fix is to separate the odd pages out with Extract Pages, crop each group with its own margins, and merge them back in order. It is slower, and it is the only way to get every page right.

Printing a cropped document

A cropped page prints at its cropped size, which may not match the paper. Scale to fit in the print dialogue, or expect a smaller image centred on the sheet.