Crop PDF

Crop PDF pages by trimming the margins, not the content

Some PDFs waste half the page on white space. Others come off a scanner with a dark strip down one side or a shadow along the top. This tool trims that away. You tell it how much to shave from the top, bottom, left, and right, and it pulls the visible edge of every page inward by exactly that much. No retyping, no dragging a selection box, no going page by page.

What actually happens to your file

Every PDF page carries a rectangle called the CropBox that tells a viewer which part of the page to draw. This tool reads each page's full size, then moves the four edges of that CropBox inward by the amounts you enter. It runs as a small Python step built on the PyPDF2 library, and it never re-renders or re-compresses the page. Your text stays selectable, links keep working, and image quality is left alone.

Here's the part people miss: the content you cropped off isn't deleted. It's still in the file, parked just outside the visible window. Cropping moves the frame, it doesn't cut the picture. That's perfectly fine for tidying margins before you print. It is not enough if the thing you trimmed off was private and you're about to email the file to someone.

One crop, applied to every page

Whatever numbers you enter get applied to all pages at once. Put 30 points in the left box and every page loses 30 points on the left. When the margins are consistent across the document, that's the whole job done in one pass. When they aren't, it's a limit worth knowing about. A file where page 1 needs a wide trim and page 40 needs a narrow one can't be done in a single run, so you'd split the file into sections and crop each one on its own.

Different pages need different trims? You can split the PDF into sections, crop each part on its own, then merge the pieces back into one file.

What happens if you crop too much

If your values would leave nothing behind, say a left and right trim that add up to more than the page is wide, the tool doesn't hand you a blank page. It checks each page, sees that the crop is impossible, and keeps that page at its original size instead. So an over-aggressive crop shows up as a page that looks untouched, not one that's been wiped. My advice: start with smaller numbers than you think you need, download, and look before trimming further. There's no live preview, so a quick check beats a re-do.

Points, inches, millimeters, or percent

Enter crop values in whichever unit suits the job. Points are the PDF default, where 72 points make one inch. Inches and millimeters are there when you're matching a physical measurement. Percent is the odd one out: it's relative to each page's own size, so 10 percent off a wide landscape page removes more actual space than 10 percent off a tall portrait page. There are one-click presets too, for a half inch, a full inch, 5 percent, and 10 percent, which cover most everyday trims.

Figuring out how much to trim

Not sure what numbers to use? Open the PDF in a reader that shows a ruler or page coordinates and measure the margin you want gone. Failing that, the presets make a decent starting point: a half inch clears the typical fat margin on a text document, and 5 percent handles most scanner borders. Nudge the values up a little at a time. It's much easier to trim a second time than to recover from cutting into your own text, and since the original content stays in the file, a re-crop with smaller numbers always brings it back.

A real example

Say you've got a 24-page slide deck exported to PDF, and every slide sits inside a one-inch band of white on all four sides that you want gone for a printed handout. Switch the unit to inches, type 1 into all four boxes, and press Crop PDF. Every page tightens by an inch on each edge in a single pass, and a few seconds later the result downloads with "-cropped" added to the file name. The slides fill the page now instead of floating in the middle of it.

Will it straighten crooked scans or shrink the file?

Two things cropping won't do. It won't straighten a tilted scan, because it only trims a straight rectangle off the edges; if the page is skewed, trimming the border leaves the skew behind. And it won't really shrink your file, since the cropped-off data is still sitting inside it. The size barely moves after a crop, so if a smaller file is the goal, you'll want a different step for that.

A crop barely changes the size, so if the document really needs to take up less space, compress the cropped PDF afterward to squeeze it down.

When cropping isn't the right tool

Cropped something out because it shouldn't be seen? flatten the cropped file so each page is re-rendered down to just the visible area and the hidden content is gone for good.

A quick word on privacy. This runs on our server, not inside your browser. Your PDF uploads over an encrypted connection, gets cropped, and the file you sent is deleted the moment the job finishes. The cropped copy you download is the only version that sticks around. And because cropping hides content rather than removing it, if the whole point of the crop was to take out something sensitive, don't lean on the crop alone before you share the file.