Resize PDF Pages — Letter to A4, Change Size
Change PDF page size to A4, Letter and more with fit or fill scaling and added margins
Runs in your browser · nothing is uploaded
Drop the PDF to resize here
Add one PDF (up to 100 MB). Adding another file replaces the current one. Files never leave your browser.
What it does
When the pages of a PDF have different sizes, printing cuts some of them off or leaves uneven margins. Documents from North America are usually Letter, while most of the world uses A4, so merged files often mix the two. This tool gives the pages a new paper size and scales the existing content to fit, centred on the page. You can also add a margin on all four sides for binding or printer limits. The live preview shows the first selected page.
How to use
- Drop one PDF on the box or press Choose PDF. The current size of the first page is shown in millimetres.
- Under New paper size pick A4, A3, A5, Letter or Legal, or Custom and type a width and height in millimetres.
- Choose the Orientation and how the Content fits: Fit, Fill or Actual size.
- Optionally type a margin in millimetres under Add margin.
- To change only some pages, choose Choose pages and type the ranges, then press Resize pages and download the result.
How it works
- Paper sizes: A3 297 × 420 mm, A4 210 × 297 mm and A5 148 × 210 mm follow ISO 216; Letter 8.5 × 11 in and Legal 8.5 × 14 in are the North American sizes. Conversions use 1 in = 72 pt = 25.4 mm.
- Scale: Fit uses
min(area width ÷ page width, area height ÷ page height)and Fill usesmaxof the same; the area is the paper minus the margins. Content is always centred. - Method: the page content is wrapped in one transformation matrix and clipped to its old visible area, so content that was hidden outside the old CropBox does not appear in the new margins. MediaBox and CropBox get the new size; TrimBox, BleedBox and ArtBox are removed.
- Limits: custom sizes from 2 to 5,080 mm (14,400 pt, the largest page size viewers handle).
- Libraries: pdf-lib (MIT) and PDF.js (Apache-2.0) for the preview.
Examples
| Goal | Settings |
|---|---|
| Print a Letter file on A4 | A4, same as each page, fit, margin 0 |
| Shrink A4 to an A5 booklet | A5, portrait, fit |
| Make a mixed-size file uniform | A4, same as each page, fit |
| 15 mm binding margin | A4, fit, margin 15 |
To trim white margins first, use Crop PDF; to renumber the pages afterwards, use Add Page Numbers to PDF.
FAQ
How do I print a Letter document on A4?
Choose A4 as the new paper and Fit as the content option. Letter (8.5 × 11 in) is a little wider and shorter than A4 (210 × 297 mm), so the content is scaled to about 97% to fit the width, with a small band added at the top and bottom. Nothing is cut.
What is the difference between Fit and Fill?
Fit scales the whole page into the new paper (inside the margins), leaving empty bands where the shapes differ. Fill scales until there are no gaps, so the edges are cut. Actual size keeps the scale at 100% and only centres the page.
Does text get blurry or the file bigger?
No. Pages are not turned into images; a scaling transform is applied to the page content, so text and graphics stay sharp vectors and the file size barely changes.
Do links and comments move too?
Yes. Links, comments, highlights and other annotations are moved and scaled with the page. Table-of-contents links that jump to a spot on another page may land slightly off.
What about a mix of portrait and landscape pages?
With orientation set to “Same as each page”, landscape pages become landscape A4 and portrait pages portrait A4. Choose Portrait or Landscape to force one direction. Rotated pages are judged as they are shown.
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