Page size is one of those things you never think about — until a print shop wants A4 and your file is US Letter, a portal insists on a specific format, or a document arrives with pages in three different sizes that look a mess stapled together. Resizing a PDF sets every page to a standard format and fits the content neatly onto it. This guide covers the sizes, how the content is fitted, and when to resize versus simply crop.
How to resize a PDF’s pages
Ream’s Resize Pages does it in your browser:
- Add your PDF to Resize Pages.
- Pick a page size — A4, US Letter, US Legal, A3 or A5.
- Download the resized PDF. Every page is scaled to that size with the content fitted in proportion and centred.
The sizes, and what they’re for
| Size | Dimensions | Common use |
|---|---|---|
| A4 | 210 × 297 mm | The worldwide standard |
| US Letter | 8.5 × 11 in | US / Canada standard |
| US Legal | 8.5 × 14 in | Contracts, legal documents |
| A3 | 297 × 420 mm | Posters, spreads, plans |
| A5 | 148 × 210 mm | Booklets, handouts |
How the content is fitted
Resizing keeps everything in proportion. Each page is scaled to fit the new size while preserving its aspect ratio, then centred — so nothing is distorted and nothing runs off the edge. Landscape pages are automatically matched to the landscape orientation of your chosen size. If instead of scaling you want to trim wide margins at the current size, that’s Crop PDF — see how to crop a PDF for the difference.
Building a uniform document from scratch? If you’re combining files, Merge PDF first, then resize the result so every page matches; and if the source was an Office file, exporting cleanly with Office to PDF before resizing gives the tidiest outcome. To reorder pages, use Organize Pages.
Is it private, and is it free?
Resize Pages runs entirely in your browser — your file is never uploaded — and it’s free, with no account and no watermark. To shrink the file’s bytes rather than its page size, that’s a separate job: see Compress PDF.
Frequently asked questions
How do I resize a PDF to A4? Add it to Resize Pages, choose A4, and download — every page is scaled to A4 with the content fitted in proportion.
Can I convert A4 to US Letter (or the reverse)? Yes — pick the target size and the pages are rescaled to it.
Will my content be stretched? No. Content is scaled proportionally and centred, so it never looks stretched or squashed.
What happens to landscape pages? They’re matched to the landscape version of your chosen size automatically.
What’s the difference between resize and crop? Resize scales the whole page to a new size; Crop hides the outer margins at the current size.
Does resizing change the file size? Not meaningfully — it changes page dimensions, not image weight. To reduce bytes, use Compress PDF.
Is my file uploaded? No — resizing runs entirely in your browser.
Getting page size right is a small thing that makes a document feel finished — consistent to read, clean to print, accepted by the portal that was fussy about it. Resize with Resize Pages, crop when it’s really margins you want gone, and compress when it’s the file size.




