How to Crop a PDF (Scanned Borders, Fix the Waste)
The short answer
To crop a PDF, open it in Preview on a Mac (built-in crop tool) or upload it to an online PDF cropper. You select the area you want to keep, the tool removes everything outside it, and you save a new file. It’s a five-minute job, and most people only discover they need it when a scan comes out with a big useless border.
Crop a PDF on a Mac (free, built-in)
- Open the PDF in Preview.
- Zoom to about 100% so you can see the edges clearly.
- Use the selection tool (the dashed rectangle) to drag around the area you want to keep.
- Tools → Crop, then File → Save.
This crops one page. For a whole document, repeat per page — or if every page has the same border, this gets tedious fast, which is where an online tool that applies one crop to all pages wins.
Crop a PDF online
An online cropper (see the PDF tools page) handles the whole document at once: upload, drag the crop box, apply to all pages, download. This is the right tool when your scan of a 20-page book has a weird margin on every page.
The honest part
Cropping a PDF is removing pixels — there’s no undo once you save. So:
- Keep the original. Crop into a copy, never over the original. You’ll thank yourself when you need the full page back.
- Cropping doesn’t shrink the file much. People crop to make PDFs lighter and are surprised when nothing much happens. The pages are smaller visually, but the embedded images often keep their full resolution. Compression is what actually slims the file.
- Text stays text. Cropping away part of a page doesn’t remove the hidden text underneath — a cropped area can still be searchable or copyable in odd cases. If you need to truly delete content, that’s redaction, not cropping.