PDF Page Size Checker
Check the exact page size of a PDF — A4, Letter, or something custom — page by page.
Knowing what size you're actually dealing with
PDFs do not announce their page size, and mixing them up causes real headaches: a document that prints with unexpected margins, pages that do not line up when merged, a file that is Letter when everyone assumed A4. This reads the dimensions of each page and tells you the size in plain terms, so there are no surprises at the printer.
Drop a PDF in and see the size of every page listed.
Why mixed sizes cause trouble
A common gotcha is a PDF where the pages are not all the same size — a Letter cover in front of A4 content, or a stray landscape page. That mismatch is what makes a document print or merge awkwardly, and it is invisible until you check. Confirming the sizes up front tells you whether you need to normalise the pages before printing or combining them.
How to check the page sizes in a PDF
- Add the PDF.
- Read each page's dimensions and paper size (A4, Letter and so on).
- Spot any pages that differ from the rest.
When one page is the wrong size
A document that mixes A4 and Letter, or hides an oversized page, prints inconsistently and looks unprofessional. Checking the sizes reveals the odd page out so you can fix it before it causes a problem at the printer.
This is common when pages from different sources are merged; a quick check catches it.
Common questions
Why are my pages different sizes?
Usually because they came from different sources — a Letter export merged with an A4 scan, for example.
What is the difference between A4 and Letter?
A4 is the international standard and slightly taller and narrower; Letter is standard in North America. Mixing them causes print scaling.
Is my document uploaded?
No. Sizes are read in your browser.
What page sizes can it identify?
Standard sizes like A4 and Letter, as well as custom dimensions, reported per page.
Why do mixed page sizes matter?
They cause documents to print with odd margins or misalign when merged. Checking first avoids the surprise.
Is my PDF uploaded?
No. The sizes are read in your browser.