Crop PDF margins without uploading

Scanner edges and wide white margins make packets look sloppy. Upload crop tools receive the whole file. LocalPdfMerge shrinks each page’s visible CropBox in your tab with pdf-lib. This guide is the long-form version of the crop PDF tool — and it leads with the honesty rule: crop is not redaction.

A worked crop: five millimetres off every side

You have a scanned letter with roughly 5 mm of white border. On crop PDF, drop the file. Leave Pages to crop as all. Enter 5 for top, right, bottom, and left. Apply crop, then Save cropped PDF. Open the download and check that text near the edges is still visible.

If the crop ate a header, clear and retry with 3 mm. A crop that would leave less than 10 pt of width or height is refused with an error instead of producing a broken page.

Crop PDF without uploading — steps

1. Open the crop tool.
2. Drop one PDF (~25 MiB soft guidance). Encrypted files fail; we do not unlock passwords.
3. Keep all or type pages such as 1, 3-4.
4. Enter millimetre margins. Optionally tick Also set MediaBox for print workflows that care about page size.
5. Apply (repeat for other pages/values if needed), save, and verify. Optional: trust Network check.

CropBox vs MediaBox — what actually changes

Viewers show the CropBox. Shrinking it hides content outside the rectangle; the bytes for that content usually remain in the file. Also set MediaBox updates the page’s media size to match the cropped rectangle. Neither option deletes the trimmed artwork. File size stays about the same because nothing is stripped.

Margins are applied in the page’s unrotated coordinate space. If a page is displayed rotated via /Rotate, “top” still means the top of the unrotated page. Fix orientation first with rotate (guide: rotate PDF pages), save, then crop.

Crop is not redaction

Do not crop to hide account numbers, faces, or medical text. Anyone can widen the CropBox again or extract embedded images and text. To drop an entire private page from the new file, use remove PDF pages (guide: remove pages). For phrase-level blackout with audit trails, use a certified redaction product. This site does not market legal-compliance redaction.

Signatures and re-save

Saving rewrites the PDF and invalidates existing digital signatures — same honesty as rotate. If a signature must remain valid, do not re-save the signed file here. Crop unsigned drafts, or keep the signed original separate.

Honest limits on local crop

• No thumbnails / no live preview. Set numbers, save, and inspect in a reader.
• Content outside the crop stays in the file; size does not shrink.
• Crops stack in memory until save or clear.
• One file at a time; soft ~25 MiB; no OCR deskew; no remote URL.
• Minimum remaining box ~10 pt in each dimension.

Related tools: rotate · remove · split · merge. Guides: rotate · remove · privacy · about · privacy policy.

When crop helps — and when it does not

Crop helps tidy scanner borders before you merge a cover into a packet, or before you send a cleaner one-pager. It does not help when the goal is secrecy, compression, or OCR. If mail rejects the file for size, cropping will not fix that — extract fewer pages or compress elsewhere.

Stacked crops and per-page margins

Apply a light uniform crop on all, then apply a heavier top margin on page 1 only. Each Apply updates the in-memory CropBox. Save once when the visible areas look right. Prefer small steps over one large guess — recovering from an over-crop means clearing and starting again from the source file on disk.

After you download

Open the cropped PDF in the reader your recipient will use. Check corners and any rotated pages. Keep the uncropped source until you are sure. Closing the tab discards unsaved applies. Publisher and corrections: about · contact (never email the PDF itself).

Crop, then split or merge

Tidy margins on a cover, save, then merge with the report — or extract a one-pager after cropping so the handout inherits the tighter box. Cropping does not reorder pages; for order, use remove/split pieces plus merge list ↑ / ↓.

For why the crop step stays on-device: local privacy guide. Policy short form: privacy.

Verify the crop before you share

Open the cropped download. Zoom to each corner. Look for clipped logos, page numbers, or binding marks. If MediaBox was also set, print a test page when print size matters. Keep the uncropped original until you are satisfied.

Then attach the file yourself. The crop step did not upload the source. Corrections to this wording: contact — quote the URL, do not attach the PDF.