How to crop PDF margins for reading on a tablet or Kindle

Why margins ruin small-screen reading

A typical A4 journal page devotes about 25mm to each side margin. That is roughly a quarter of the page width doing nothing except being white.

Your reader has to fit the whole page onto the screen, margins included, so a quarter of your screen is showing blank paper and the text shrinks to fit what is left. Crop the margins and the same screen now holds only the text block — which means the text is drawn larger, at the same resolution, with no loss of quality.

This is the difference between a paper being readable on a tablet and being something you give up on after two pages.

Cropping the pages

Check a page with a wide table or a full-width figure before committing. Those are usually the widest content in the document, and a crop that suits the body text can clip them.

1. 1Open the Crop PDF tool and choose your file.
2. 2Drag the crop handles inwards until the frame sits just outside the text.
3. 3Leave a few millimetres of margin — text touching the screen edge is uncomfortable to read.
4. 4Check a few pages, especially ones with figures, then download.

The header and footer question

Journal pages carry running headers, page numbers and sometimes a DOI or copyright line. Cropping top and bottom aggressively removes them, which gains screen space at a cost.

Keep the page numbers if you will cite the paper — a citation needs them, and recovering them later means going back to the original. Remove the running header, which repeats the journal name on every page and tells you nothing after the first.

Cropping does not delete anything

This is the reassuring part, and it is worth understanding. Cropping a PDF sets a visible boundary on the page rather than cutting the content away. The material outside the crop box is still in the file; it is simply not displayed.

That means cropping is non-destructive and reversible — the crop can be widened again later without loss. It also means file size does not go down, which surprises people who crop hoping to shrink a file. Nothing was removed, so nothing was saved.

The practical caveat: because the content is still there, cropping is not a way to hide sensitive information. Text cropped out of view can be recovered. If something must be gone, it has to be genuinely removed, not framed out.

Never use cropping to redact. The hidden text is still in the file and is trivially recoverable by anyone who thinks to look.

Getting it onto your device

For an iPad or Android tablet, the cropped PDF works directly in any reader — copy it across and open it.

For a Kindle, email the file to your Send-to-Kindle address, or use the Send to Kindle app. Kindle's own PDF handling is limited and does not reflow text, which is exactly why cropping matters so much there: it is the only way to make the text bigger.

If the paper is a scan rather than a digital typeset document, crop it and then run OCR, so you can search and highlight it as well as read it.

When cropping is not the answer

If pages have different layouts — a document mixing portrait text pages with landscape figures — a single crop applied to everything will clip the wide pages. Split those out and treat them separately.

If the text is genuinely too small even after cropping, the problem is the source resolution or your screen size, and no cropping helps. A reflowable format like EPUB is the real answer where one exists.

And if you want to save paper rather than screen space, cropping is the wrong tool — N-up printing puts two or four pages on a sheet and is what you actually want.