What this tool does
- Drag a crop box — draw the area you want to keep straight onto a page preview
- Trim margins by the millimetre — type exact top, bottom, left and right amounts to shave off
- Apply to one page or all — crop the whole document to the same box, or treat a single page separately
- Non-destructive — the page's crop box changes; the underlying text and graphics stay intact and selectable
Why crop a PDF
- Reclaim the thick white margins on a scanned book page so the text fills an e-reader screen
- Cut a header or footer with a stale letterhead off every page
- Pull one chart out of a wide report page for a slide
- Remove the black edges a flatbed scanner left around a smaller sheet
Crop box vs media box
A PDF page actually carries several rectangles. The media box is the physical sheet; the crop box is the region a viewer is told to display. This tool sets the crop box (and matches the media box to it on save) so that readers, browsers and printers all show the trimmed page. Because nothing is rasterised, the text outside the crop is simply no longer displayed rather than re-rendered — if you need content genuinely removed from the file, use Redact PDF instead.
Frequently asked questions
Are my PDFs uploaded anywhere?
No — the file is opened and rewritten entirely inside your browser using JavaScript. Nothing is uploaded to a server, so your document never leaves your device.
Is the cropped-away content really gone?
No — cropping hides it by shrinking the displayed area, and a determined reader could widen the crop box again. To permanently destroy content, use Redact PDF, which rasterises the page so the original text no longer exists in the file.
Can I crop each page differently?
Yes — switch off Apply to all pages and the crop box you drag applies only to the page you are previewing. Step through pages to set each one.
Will cropping break selectable text?
No. Text inside the crop stays fully selectable and searchable because the page content is copied across unchanged.
What units are the margin fields in?
Millimetres, converted to PDF points (1 mm ≈ 2.835 pt) when the file is written.