Cropping a PDF trims the empty space around the page so the content sits where you want it. Scans arrive with a grey band down one side, exported slides carry a wide white border, and a document prepared for A4 rarely looks right once it is read on a phone. This tool takes measured margins off the top, right, bottom and left, on every page or on a range you pick.
The file never leaves your browser. Pages are read and rewritten on your own machine, which matters when the document is a contract, a payslip or a scanned identity record.
Numbers instead of a drag handle
Dragging a box over a preview feels natural for one page and falls apart at forty. Most cropping jobs are repetitive: take fifteen millimetres off the top of a whole scanned batch, or shave the same border from every exported slide. Typing the four values once gives you an identical result on every page, and you can repeat it next week with the same numbers.
Each value is measured inward from that edge of the page. Leave a side at zero to keep it exactly as it is.
Millimetres and PDF points
A PDF measures everything in points. One millimetre is 2.8346 points, and that conversion is applied for you, so you can think in the units printed on a ruler. An A4 page is 210mm by 297mm, which the file stores as roughly 595 by 842 points.
The tool reads each page's media box, subtracts your four margins, and writes the result back as the crop box. Page content stays exactly as it was; what changes is the window a reader displays.
When the crop is too aggressive
Margins that add up to more than the page leave nothing to show, and a file like that opens badly or refuses to open at all. If that would happen, the tool stops and names the page along with its real size in millimetres, so you can see how much room you have to work with before trying again.
Pages in one document are not always the same size. A mixed file with a landscape chart among portrait text may need two passes with different values, one for each page range.
Cropping part of a document
Switch to a page range when only some pages need it. The range syntax matches a print dialog: commas separate single pages, a hyphen makes a range, and 1,3,5-8 covers five pages. Clicking the page thumbnails fills the box in for you.
Frequently asked questions
Is my PDF uploaded to crop it?
No. The file is read in your browser and the cropped version is written there too. Nothing is transmitted, so a confidential scan or a signed contract stays on your device throughout.
How many millimetres should I take off?
Start with ten and look at the result. Scanner borders are often between five and twenty millimetres, while an exported slide deck usually needs more. Cropping again on the output is fine if the first pass was cautious.
Does cropping make the file smaller?
Barely. The trimmed area is hidden, not deleted, so the page content and its images are all still stored. Use a compression tool if file size is the goal.
Can I undo a crop?
Keep the original file. The crop is written to the output you download, and the source PDF on your computer is untouched, so reverting means going back to it.
Why does one page look different from the others?
Pages can have different dimensions inside a single PDF. A fixed margin removes the same physical distance from each one, which looks heavier on a smaller page. Crop those pages separately using a page range.
Related Utilities You Might Need
Scanned PDF Converter
Simulate real scanned sheets from loaded PDF pages by adding skews, blurs, and scanner noise.
Merge PDF
Combine several PDFs into one file in any order. Runs entirely in your browser, so nothing you merge is ever uploaded.
Split PDF
Cut a PDF into separate files, every few pages or by an exact range. Processed on your device, never uploaded.