A4 and US Letter are not the same shape
Most of the world uses A4 (210 × 297 mm); the United States and Canada use Letter (8.5 × 11 inches, 216 × 279 mm). A4 is a little narrower and noticeably taller, so a page cannot simply be “converted”: either the content changes size, or some paper is left blank, or something is cut off. Here is what each choice does to an ordinary page:
| Converting | Fit (default) | Keep size |
|---|---|---|
| US Letter → A4 | Content at 97.3%: 11 pt text prints at 10.7 pt. A blank band of 12.6 mm at the top and bottom. | Content at 100%. 8.4 pt (3 mm) is cut from each side, usually only margin. |
| A4 → US Letter | Content at 94.1%: 11 pt text prints at 10.3 pt. A blank band of 9.2 mm at each side. | Content at 100%. 24.9 pt (8.8 mm) is cut from the top and bottom, where headers and page numbers often sit. |
Fit is the safe choice: nothing is lost and the small change in text size is hard to notice in print. Keep size is right when the document has wide margins and the size of the text matters, for example a form that will be filled in by hand. Whenever Keep size or Fill would cut something off, the tool draws each affected page, looks for ink in the strip that falls outside the new paper, and names the pages, so a lost page number or header does not come as a surprise at the printer. A page with only blank margin there is reported as safe.
Links, bookmarks and form fields keep working
The quickest way to build a page resizer is to make a new blank page in the new size and draw the old page onto it as one object. It looks right, but everything that is not ink is left behind: links stop working, bookmarks lose their pages, comments disappear and fillable form fields are gone. We measured that shortcut against this tool on a 5-page report with 4 links and 3 bookmarks:
| Converted to A4 | Links working | Bookmarks | Selectable text pieces |
|---|---|---|---|
| New page with the old page drawn on it | 0 of 4 | 0 of 3 | 137 of 137 |
| This tool | 4 of 4 | 3 of 3 | 137 of 137 |
Here the original page is kept and changed in place. Its content is scaled and centered, and everything that has a position is moved by exactly the same amount: the clickable area of each link, the target that a link or bookmark jumps to, form fields, highlights, ink drawings and other comments. In our tests every link area still sat on the same words, every internal link still landed on the same spot, and the fields of a fillable form could still be filled in after resizing.
Pages of mixed sizes and turned pages
- Already the right size? Those pages are left exactly as they are; only the others change. The report says how many were changed, from which sizes, and by how much.
- Landscape pages stay landscape by default (Same as each page), so a wide table becomes landscape A4 rather than shrinking onto a portrait page. Choose All portrait or All landscape to force one direction.
- Pages turned with the rotate setting and pages with a crop box (a hidden border some programs leave around the visible page) are measured as you see them. Anything outside the old visible area stays hidden on the new page.
- Only some pages: type a range such as
3, 7-9to resize those and leave the rest alone.
Text and drawings are scaled as they are, never turned into pictures, so they stay sharp, selectable and searchable, and the file stays about the same size. Everything happens inside your browser: the PDF is not uploaded and there is no page limit. To fit two pages on one sheet instead, print with “2 pages per sheet” in your print dialog; to make the file smaller in megabytes rather than in paper size, use Compress PDF.