PDF Page Size Checker
Find out what paper size a PDF really has. The checker reads every page’s boxes and reports the visible size in millimetres, inches and points with its standard name – A4, US Letter, A3, Legal and others – its orientation and rotation, groups consecutive pages of the same size, and warns about mixed sizes, crop boxes and print production boxes.
- Files stay on your device
- No sign-up
- Free to use
How to use PDF Page Size Checker
- Drop a PDF onto the page.
- Click “Check page sizes”.
- Read the summary and the size of each page range.
- Convert pages with the size converters if needed.
PDF Page Size Checker features
Three units
Millimetres, inches and PDF points.
Standard names
ISO A and B sizes and US paper sizes.
Page ranges
Consecutive pages of the same size grouped.
Rotation
Displayed size after /Rotate.
Boxes
Crop, trim and bleed boxes detected.
Mixed sizes
Warning with a count per size.
When to use PDF Page Size Checker
- Checking a file before printing or sending it to a printer.
- Verifying submission requirements such as A4 only.
- Finding odd pages in merged documents.
- Preflighting print files for trim and bleed.
PDF Page Size Checker FAQ
Which size is reported?
The visible size: the crop box if one is set, otherwise the media box, with width and height swapped for pages rotated by 90° or 270°.
What are trim and bleed boxes?
Print production boxes: the trim box is the final cut size, the bleed box includes the extra area that is trimmed off. Print-ready files often have both.
Why does my A4 file show “Custom”?
Its size differs from A4 by more than 2 mm, for example after scanning or scaling.
What is a point?
The PDF unit: 1/72 of an inch, about 0.353 mm. A4 is 595 × 842 points.
How do I fix mixed sizes?
Use the PDF Page Size Converter, A4 Converter or Letter Converter.
Is my PDF uploaded?
No. It is read in your browser.
Page sizes and boxes in PDF
Every PDF page defines its size with boxes. The media box is the full sheet; the crop box is the part viewers show; the trim and bleed boxes describe the finished size and the printing overflow for professional print. Pages can also carry a rotation that turns them for display.
The size people mean is usually the visible one, so the checker uses the crop box (or the media box when none is set) and applies the rotation. It converts the dimensions to millimetres and inches and compares them with standard paper sizes, allowing a small tolerance for rounding.
Documents assembled from several sources often mix sizes: US Letter pages among A4, a landscape table, a scanned page that is a few millimetres off. Printers handle such pages differently, so the checker lists every distinct size with the pages that use it.
Values come directly from the file structure read with qpdf, so they are exact, and nothing leaves your device.