Crop PDF

What this does

This crops the pages of a PDF — drag a box over the page, type margins in millimetres, or press one button and let it trim the white space away by itself. The file is edited in your browser and never uploaded.

Cropping hides. It does not delete.

This is the one thing worth knowing before you crop anything, and most tools never say it. A PDF page has two rectangles: the MediaBox, which is the sheet, and theCropBox, which is the part a reader shows you. Cropping sets the second one. Everything outside it is still in the file — every word, every picture — and anyone who opens the file in the right software can set the box back and see all of it.

So cropping is perfect for tidying a scan, trimming margins to read on a small screen, or cutting a two-up scan into pages. It is not a way to remove something you don't want seen. If that's what you need, the content has to be taken out rather than hidden, and this is the wrong tool.

Trimming the white margins

A scanned book or an article printed to PDF is mostly margin, and on a phone or an e-reader that margin is most of the screen. Trim the white margins renders each page, finds where the ink actually is, and crops to it with whatever breathing room you ask for.

It works on scans as well as on text, because it looks at pixels rather than at glyphs. It estimates the colour of the paper from the corners of the page first, so a cream or grey scan is not mistaken for a page covered in ink. And it ignores single stray pixels, because scanner speckle in a margin would otherwise defeat the whole thing — one dark dot in the corner and there is nothing to trim.

How to use it

1. Drop in a PDF.
2. Press Trim the white margins, or drag the box on the page yourself.
3. Choose whether the crop applies to every page, this page, or every page mirrored.
4. Step through a few pages to check, then save.

Things worth knowing

• Nothing is re-rendered. A crop is two rectangles on the page, not a redraw, so text stays selectable and artwork stays sharp. The file barely changes size — and it does not get smaller, because nothing was removed.
• Both boxes are set. Readers display the CropBox; printers trim to the TrimBox. Setting only the first is how a cropped page comes back from a print shop the size it always was.
• Pages already turned are handled. A page carrying a rotation is shown turned, so the box you drag along its top edge is stored down the side of the sheet. That conversion happens for you.
• Mixed page sizes are respected. A crop given as margins is taken off each page's own edges, so a document that mixes A4 and letter doesn't end up with pages cropped to different content.

Frequently asked questions

Is my file uploaded?

No. It's read and edited in your browser. You can watch the network panel while it runs, or disconnect from the internet once the page has loaded and crop anyway — it still works.

Can someone recover what I cropped out?

Yes. Cropping hides; it doesn't delete. Anything outside the box is still in the file. Don't use a crop to hide something confidential.

Why didn't the file get smaller?

Because nothing was thrown away. If you want a smaller file,Compress PDF is the tool for that.

Why is one page cropped differently from the rest?

Either you applied a crop to that page alone, or the automatic trim found its ink in a different place — a page with a wide table or a full-width picture keeps more of the sheet than a page of plain text.