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How to crop a PDF on a Mac

Crop a PDF on a Mac for free in Preview, one page or all of them, and what we found when we checked: the part you crop away is still inside the file.

The problem

Wide white margins, the edge of a scanner bed, a receipt in the middle of a big page: you want only the part that matters. Cropping does that in seconds, but it does not do what most people assume about the part you cut away.

How do I crop a PDF on a Mac?

Open it in Preview, drag a box around the part to keep with the Rectangular Selection tool, and press Command K. That crops the page, for free, with nothing to install.

  1. Open the PDF in Preview.
  2. Choose Tools > Rectangular Selection, or the selection button in the Markup toolbar, and drag a box around the part to keep.
  3. Choose Tools > Crop, or press Command K.
  4. Choose File > Export as PDF to save a cropped copy.

How do I crop every page of a PDF at once?

Show thumbnails with View > Thumbnails, select all the pages with Command A, then draw the box and crop. Preview applies the same box to every selected page.

How do I crop to an exact size?

Open the Inspector with Command I while the box is drawn: it shows the selection's size, and you can switch the unit to inches or millimetres. To make pages one paper size instead, see make every page A4 or Letter.

Does cropping a PDF delete the part you cut off?

No. Cropping tells apps which part of the page to show; everything outside is still in the file. We made a page with a receipt in the middle and an account number near the bottom, and cropped to the receipt. The cropped file was slightly larger than the original, 8,798 bytes against 8,760, and the account number was still in it: the free pdftotext tool printed it straight away.

pdftotext cropped.pdf -

Does printing to PDF remove what was cropped?

It is often suggested, and in our test it did not. We drew the cropped page into a new PDF the size of the crop, the way printing to a PDF draws a page. The account number no longer showed when the page was read normally, but it was still inside the new file, placed outside the page, and reading past the page edge brought it back.

Measured on 16 October 2026 on a MacBook Air (M1), macOS 27.0.1, with made test files. Cropping was applied by changing the page's crop box, the same thing Preview's Crop changes; the redraw drew the cropped page into a new PDF sized to the crop.

How do I really remove part of a PDF page?

Redact it. Preview's Redact tool and Simply PDF's Redact remove the content itself, not just the view of it. Then search the saved copy for a word you removed: how to redact a PDF on a Mac shows the check.

Our take

Crop for looks, redact for privacy. Cropping is the right tool for margins and scanner edges, and the wrong one for anything you would not want the reader to see, because the cut part travels with the file.

After cropping

If the trimmed pages now differ in size, or the file is still large, Simply PDF can tidy the rest on your Mac: compress with a preview, reorder and split. Those tools need a key; opening and merging are free.

Questions

How do I crop a PDF in Preview?

Drag a box with Tools > Rectangular Selection around the part to keep, then choose Tools > Crop or press Command K, and export a copy.

Does cropping a PDF remove the hidden part?

No. It is still in the file. In our test a cropped account number was printed by pdftotext from the cropped file. Use redaction to remove content.

Does cropping make a PDF smaller?

No. The cut part is still stored, so the file stays about the same size; ours grew by 38 bytes.

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