Crop PDF Pages Online

How to Crop a PDF

1. Select a PDF.
2. Draw a crop box or enter exact margins in points.
3. Choose whether to preserve the page size or resize it to the crop bounds.
4. Choose current page, selected pages, or all pages, then export.

What this tool changes

• Either hides content outside the crop box (page size unchanged) or resizes the page to the crop bounds, depending on the mode you choose.

What it preserves

• Content inside the crop area.

Good to know

• Crop settings are never applied to pages you did not select — each application (current, selected, or all pages) is an explicit choice.

The two modes, precisely

A PDF page carries two rectangles that matter here. The MediaBox is the sheet — the full physical page. The CropBox is the window — the region a viewer or printer actually shows.

Preserve page size sets the CropBox and leaves the MediaBox alone. The page's declared dimensions are unchanged and only the visible region shrinks. This is the safer default, because nothing about the page geometry is altered: reset the crop and you are exactly where you started.

Resize to the crop bounds sets both. The page's declared size becomes your crop rectangle. Use it when something downstream reads page dimensions — a printer, a layout program, a submission system that checks page size. The practical test is simply whether anything after you cares how big the page claims to be.

Margins are in points, and a point is 1/72 inch

Seventy-two points make an inch, which keeps the conversions easy: a quarter-inch trim is 18 points, a half-inch is 36, an inch is 72, an inch and a half is 108.

A US Letter page is 612 × 792 points and A4 is 595 × 842. Those two numbers tell you immediately whether a margin is plausible — trimming 100 points from each side of a 612-point-wide page leaves 412 points of content, which is fine; trimming 300 leaves 12, which is not. Margins that would consume the whole page are rejected rather than producing blank sheets.

Measure rather than guess. Note where content actually starts relative to the page edge, subtract a few points for safety, and use that. Guessing goes one of two ways: too timid, so you crop three times, or too aggressive, so you clip a page number off the bottom and find out after printing.

What cropping never does

It does not delete. Content outside the crop is still in the file, hidden from view and from print, and it returns the moment anyone widens the crop box — which any PDF editor can do in seconds. Cropping a sensitive number out of a margin does not remove that number from a file you are about to send.

It does not make the file smaller either, and this catches people trying to meet an email limit. The bytes are in the content and the content is all still there. Measured on a five-page document cropped by a full inch on every side, the file grew by about 140 bytes — the cost of writing the new box entries.

If the goal is a smaller file, why is my PDF so large covers what actually works. If the goal is removing something sensitive, the only reliable answer is to remove the whole page with Delete PDF Pages.

What each crop mode costs, measured

Cropping is the operation people most often expect to shrink a file, so it is worth putting a number on it rather than an adjective. We cropped half an inch off every edge of a three-page scan of just under four megabytes, in both modes, and compared the bytes.

Hiding the margins made the file 186 bytes larger. Resizing the pages to the crop bounds made it 192 bytes larger. Neither saved anything, and the reason is the same in both cases: a crop writes a rectangle, and the content outside that rectangle is still in the document, waiting for anyone who widens the crop again.

If a file is too heavy, cropping is not the lever. Deleting a page frees essentially that page’s entire weight, and re-scanning at a lower resolution is the other real saving. The measurements page has both, with methods.

What cropping does leave alone is the document itself. Because it edits the pages already there rather than rebuilding the file, the title, author, subject, and creator all survive a crop — which is not true of reordering, removing, or extracting pages.