Resize a PDF to A4 (210 × 297 mm) without uploading it

Letter to A4: what changes on the page

US Letter is 612 × 792 points, A4 is 595 × 842. A4 is 17 points narrower and 50 points taller, so a Letter page scaled to fit A4 is reduced to about 97% and sits with roughly 25 points of extra white space above and below the content. Text stays sharp because the page is scaled as vector content, not rasterised.

When to keep the content size instead

Choose Keep content size if the document has links, bookmarks, or form fields you need to preserve, or if the pages are already A4-sized drawings that only need the page box corrected. In that mode nothing is scaled, so a larger page may be clipped on the right and top; check the preview before downloading.

• Fit to page: scales and centres, drops links and form fields
• Keep content size: preserves links and fields, may clip or add white space
• Mixed sizes in one file: every page becomes A4 either way

Printing an American document on A4 paper

Printers outside North America default to A4. A Letter PDF printed on A4 without resizing either gets cut off at the bottom or shrunk unpredictably by the driver. Resizing the PDF to A4 first gives you a predictable result on any printer and removes the "fit to page" guesswork from the print dialog.

Submitting to a venue that requires A4

Many universities, conferences outside the US, and government portals require A4. Resize the exported PDF, then run Remove PDF Metadata if the submission is anonymous and Compress PDF if the portal has a size limit. The IEEE paper margins page lists the A4 template margins if the layout itself must change.

Other sizes

The same tool resizes to US Letter, Legal, A5, Square, or any custom width x height in points: A3 is 842x1191, A0 is 2384x3370, and 72 points make an inch.