PDF page sizes for scans: why yours isn’t “A4” and why that’s fine

Open a scan's file info and you may see page dimensions that match no paper standard. Relax: PDF pages can be any size, and for scans, matching the document's shape is the faithful choice.

How scan pages get their shape

ToPDF crops to your document's actual outline, so an ID card yields a small card-shaped page, an A4 letter an A4-proportioned page. The page is the document — no arbitrary white borders, no content shrunk into a mismatched frame.

Viewing and printing behaviour

• Screens don't care: readers scale pages to the window; proportions rule, absolute size doesn't.
• Printers adapt: every print dialog has “Fit to page” — your card prints centred on A4/Letter at a sensible size, or at 100% (“Actual size”) if you want true dimensions.

When a strict page size is demanded

Rarely, a portal insists on “A4 PDFs”. Easiest compliant path: print the scan to PDF via your browser/OS (Print → Save as PDF → paper size A4) — your document lands centered on a genuine A4 page. The scan's quality carries through; only the canvas changes.

Frequently asked questions

Why not always pad scans onto A4 automatically?

Because most consumers of scans — humans and systems — prefer content-only pages. Padding wastes screen space and adds nothing but white; a faithful shape is the better default.

Do odd page sizes break any readers?

No — arbitrary sizes are standard PDF and universally supported, from browsers to office printers.