Crop PDF
Cut unwanted margins or scanner borders from PDF pages and save the tighter document.
Processed on your device — no upload
How to crop PDF
- Choose the PDF with margins you want to trim.
- Enter how many millimetres to cut from each edge.
- Press crop. The tighter PDF downloads to your device.
How it works
Every PDF page carries two rectangles. The media box is the physical size of the sheet. The crop box is the region a reader actually displays and prints. Cropping does not cut anything away — it shrinks the crop box, and the content outside it simply stops being shown.
That has a consequence worth knowing: cropping is reversible and lossless. The text and images beyond the new boundary are still in the file, so the page can be restored later by widening the crop box again. It also means cropping does not reduce file size, and it does not remove sensitive content from the margins. If something must genuinely be gone, cropping is the wrong tool.
Measurements here are in millimetres, converted internally to PDF points at 72 per inch. The crop box is positioned from the bottom-left corner of the media box, so trimming 10mm from the left and 10mm from the bottom moves the origin inward by that much, and the width and height shrink by the totals you gave for each axis.
The tool refuses any combination that would leave a page with no area at all, naming the page that would have vanished rather than producing a broken document.
A worked example
You scanned a book chapter at A4, but the book is smaller than the glass, so every page has a wide grey border down one side and a black strip along the top. Reading it on a tablet wastes half the screen.
Choose chapter.pdf. Measuring the scan, the top strip is about 15mm and the grey edge on the right is about 30mm; the left and bottom are close to clean.
Enter 15 for top, 30 for right, and 5 for left and bottom to tidy the remaining edges. Leave Apply to on Every page. Press Crop and download — you get chapter-cropped.pdf and Cropped 32 pages. On a tablet the text now fills the screen.
Two things to check afterwards. First, the file size will be essentially unchanged: the cropped-away content is still in there, just not displayed. Second, if the scan drifted — common with a hand-fed book — a single margin will not suit every page. In that case, crop conservatively for the whole document, then run the worst pages separately by switching Apply to to Selected pages and listing them.
If the pages are also sideways, rotate them first — the margins you name are relative to the page as it will be displayed.
Questions
How do I trim edges off every page at once?
Set the margins and apply them to the whole document. A scanner's black border is usually the same width on every page, so one setting clears all of them.
Can I cut the edges off a scanned page?
Trim from any side to remove a scanner's black border or an over-wide margin. This is a crop rather than a resize page operation: the content keeps its size and the visible area shrinks.
Does cropping delete the content in the margins?
No. It shrinks the crop box, which is the area a reader displays. The content outside it remains in the file and can be revealed again by widening the box, so cropping must never be used to hide sensitive information.
Will cropping make my file smaller?
No, and this surprises people. Nothing is removed, so the file size stays essentially the same. Cropping changes what is shown, not what is stored.
Is my PDF uploaded?
No. The crop box is edited in your browser on your own device. There is no backend to this site, so the document is never transmitted.
What units does it use?
Millimetres, converted internally to PDF points. Entering 10 in the top field trims one centimetre from the top edge of the displayed page.
Can I crop only some pages?
Yes. Switch "Apply to" to "Selected pages" and enter a selection like 2, 5-7. This is useful for scans where a few pages drifted and need more trimming than the rest.
What if my margins are too large?
The tool stops and names the page that would have been reduced to nothing, rather than saving a document with an unopenable page.
Will the cropped PDF print correctly?
Yes. Printers honour the crop box, so the page prints as displayed. Depending on your printer settings the smaller page may be scaled up to fit the paper.
How do I undo a crop?
Keep your original file. That is the simplest route. Because nothing was deleted, the crop can also be widened again in a full PDF editor.
Does this crop PDF pages permanently?
It sets the crop box, which is what every viewer and printer reads. Crop PDF pages this way and the content outside the box stops being displayed or printed — though the underlying objects remain in the file, which is why cropping is not a way to redact something.
Can I crop PDFs with different page sizes?
Yes. Crop PDF files whose pages vary — a scanned book where every sheet sits slightly differently, for instance — since the margin you set is applied relative to each page's own box rather than to a fixed size.