Decide whether one crop fits the whole document
An all-pages crop works best when every page has similar margins and orientation. Look through the PDF first: a landscape table, a larger diagram or a page number close to an edge may need a different selection.
For example, a ten-page scan with the same wide white border is a good candidate for one crop. A collection of receipts with different dimensions is better handled page by page.
Set the crop using a representative page
Open the PDF in the Crop tool and position the crop box around the content you want to keep. Leave a little space around text instead of drawing exactly against the letters.
Use the option to apply the crop to all pages when their layouts match. For mixed layouts, set individual page crops and check each preview before generating the output.
Check the saved PDF
Download and reopen the result. Inspect the first, middle and last pages, plus any pages with tables or a different orientation. Make sure footnotes, page numbers and signatures are still visible.
Keep the source PDF until you have checked the complete result. If an edge is cut off, return to the original and use a larger crop area.
Cropping is not redaction
Cropping can change the visible page boundary without deleting the content outside it. Do not use it to hide account numbers, addresses or other information that must not remain recoverable.
Use a dedicated redaction workflow for information removal and inspect the exported copy. The distinction matters even when the cropped page looks correct in your viewer.
Cropping is not compression either
Removing visible margins does not necessarily remove the underlying page data or make the file substantially smaller. If your goal is an upload limit, crop for appearance first and then use the compressor if needed.
The crop tool runs on your device. On a phone, work with a manageable document size and leave the browser open until the download is ready.