Quick answer
Each page has its own boundaries and rotation. The size most people see is the intersection of MediaBox and CropBox after page rotation; a printer may also care about the TrimBox and BleedBox. This checker reports all pages in points, inches, and millimeters, then lets you export the evidence.
No PDF upload
Check your PDF page dimensions
Ready. Choose a PDF to inspect its page dimensions and boxes.
PDF report
| Page | Detected size | Inches | Millimeters | Points | Effective box differences |
|---|
What the five PDF page boxes mean
A PDF page can carry several nested boundaries. The terms below follow the published PDF 1.7 specification and Adobe Acrobat’s page-box guidance.
MediaBox
The physical medium boundary. It is required and forms the outer page extent.
CropBox
The visible region used when the page is displayed or printed. It defaults to MediaBox.
TrimBox
The intended finished page after physical trimming. It matters for print production.
BleedBox
The production clipping region that allows artwork to extend beyond the final trim.
ArtBox
The creator’s intended meaningful content area, including deliberate white space.
Why the values can differ: cropping a PDF can hide content without removing it. Adobe notes that cropping alone does not reduce the file size; resetting the page size can reveal the original content again.
Common PDF page dimensions
PDF default user-space units are points: 72 points equal one inch. A-series entries below use the trimmed sizes standardized by ISO 216:2007. Small rounding differences are normal because millimeters do not always convert to an exact decimal number of PDF points.
| Paper | Millimeters | Inches | Approx. PDF points | Common use |
|---|---|---|---|---|
| A0 | 841 × 1189 mm | 33.11 × 46.81 in | 2383.94 × 3370.39 pt | Large posters and technical drawings |
| A1 | 594 × 841 mm | 23.39 × 33.11 in | 1683.78 × 2383.94 pt | Posters and plans |
| A2 | 420 × 594 mm | 16.54 × 23.39 in | 1190.55 × 1683.78 pt | Diagrams and small posters |
| A3 | 297 × 420 mm | 11.69 × 16.54 in | 841.89 × 1190.55 pt | Charts, spreads, and drawings |
| A4 | 210 × 297 mm | 8.27 × 11.69 in | 595.28 × 841.89 pt | International office documents |
| A5 | 148 × 210 mm | 5.83 × 8.27 in | 419.53 × 595.28 pt | Booklets and small forms |
| US Letter | 215.9 × 279.4 mm | 8.5 × 11 in | 612 × 792 pt | North American office documents |
| US Legal | 215.9 × 355.6 mm | 8.5 × 14 in | 612 × 1008 pt | Contracts and legal forms |
| US Tabloid | 279.4 × 431.8 mm | 11 × 17 in | 792 × 1224 pt | Newsletters and folded spreads |
| US Executive | 184.15 × 266.7 mm | 7.25 × 10.5 in | 522 × 756 pt | Short business documents |
Download the paper-size reference as CSV
How the checker decides what size you see
- Read every page independently.
The browser opens the PDF with PDF-LIB 1.17.1 and reads the effective MediaBox, CropBox, TrimBox, BleedBox, ArtBox, and rotation for each page.
- Resolve the visible box and rotation.
The displayed region is the intersection of MediaBox and CropBox. A 90° or 270° page rotation then swaps its width and height. That is why a stored 612 × 792 point page can display as 792 × 612 points.
- Match common paper sizes with tolerance.
A two-point tolerance absorbs harmless decimal rounding while keeping clearly custom dimensions labeled Custom.
- Flag mixed dimensions and boxes.
The summary counts distinct displayed sizes, rotated pages, and pages where effective box coordinates differ by more than half a point.
- Export the evidence.
CSV contains one row per page. JSON preserves the complete coordinates for all five effective page boxes.
Reproducible page-box test fixture
The downloadable four-page fixture contains Letter, rotated A4, custom 6 × 9 inch, and Tabloid pages. One page has deliberately different CropBox, TrimBox, BleedBox, and ArtBox coordinates. Use it to verify this checker or compare another analyzer.
Download the four-page test PDF Fixture manifest and expected results
When page size matters
Print shops and bleed
TrimBox should describe the finished piece, while BleedBox allows artwork beyond the cut edge. A visible Letter-sized page alone does not prove the file is print-ready.
Court and government filing
Portals can require Letter, Legal, or A4. Check every page because one scanned exhibit or spreadsheet can introduce a different size.
Booklets and mixed sources
Merging files can combine Letter, A4, landscape, and custom pages. Mixed sizes may scale unpredictably during duplex printing or booklet imposition.
Exact-size artwork and patterns
Print at 100% or Actual Size only after confirming the intended page dimensions. “Fit” or “Shrink” changes physical scale.
Caveats and assumptions
This tool reports page geometry stored in the PDF. It does not measure objects inside the artwork, printer hardware margins, or the physical result after a print dialog scales the page. Password-protected PDFs must be unlocked before inspection. Standard-name detection is a convenience label; the exact point, inch, and millimeter values remain authoritative for the inspected file.
The first use may download PDF-LIB from jsDelivr. The selected PDF is read from local browser memory and is not included in analytics or sent to GoPDFConverter. Exported CSV and JSON files are created locally.
Frequently asked questions
How can I check the page size of a PDF?
Why does a PDF have more than one page box?
Can one PDF contain different page sizes?
Does cropping a PDF change its physical page size?
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