PDF Page Size Checker
Read PDF page sizes, rotations and boxes locally; export a geometry report.
This tool runs entirely in your browser. Your data is never uploaded, never stored, and never leaves your device.
Reads every PDF page’s visible dimensions, rotation, UserUnit and page boxes, distinguishing explicit, inherited and default geometry.
How to use it
- 1Choose a local PDF up to 25 MiB and 300 pages.
- 2Inspect all page sizes and review any mixed-size groups or box warnings.
- 3Select a page for details or download the complete JSON/CSV report.
Example
- Input
- 612 × 792-point page; rotation 90°; UserUnit 1
- Output
- Visible: 792 × 612 pt · US Letter · landscape
The report never changes or renders the source PDF.
What happens to your data
PDF contents stay in a local worker. Reports omit the original filename, text, document properties and fingerprint, but include page geometry.
Last updated October 2026
Check the page sizes inside a PDF before printing, binding or combining documents. This local inspector reads every physical page and reports its visible dimensions, orientation, declared rotation and UserUnit scale. A summary groups similar dimensions so an unexpected Letter, A4, landscape or custom page is easier to find.
Open a page’s details to distinguish MediaBox, CropBox, TrimBox, BleedBox and ArtBox, including whether each value is explicitly on the page, inherited where allowed, or supplied by the PDF default. Download the complete geometry as JSON or CSV. Your PDF is inspected, not changed or rendered.
How it works
Choose one local PDF and select Inspect PDF sizes. A browser worker parses the file, reads the page dictionaries and produces a report without opening document actions, following links or drawing page content. The input is limited to 25 MiB and 300 pages. Encrypted PDFs, damaged structures and unsupported geometry are rejected with no successful report. Cancel, Clear or choosing another file stops the active worker and invalidates old output; a worker has a 10-second deadline after startup. A timeout is an incomplete inspection, not a clean result.
MediaBox describes the physical page boundary. CropBox describes the region normally displayed or printed and defaults to MediaBox when absent. TrimBox, BleedBox and ArtBox default to CropBox when absent. MediaBox, CropBox and rotation can be inherited from the page tree. The report keeps these sources explicit: a default TrimBox does not prove that a print designer authored trim information. Raw coordinates are preserved as four PDF user-space numbers. Opposite corners can be reversed; dimensions are normalized and that case is flagged.
A standard PDF user-space unit is one seventy-second of an inch. A positive UserUnit scales that relationship. Supported values are greater than zero and at most 75,000; absence means 1, and the report distinguishes an explicit value from the default. For example, a 306 × 396 user-unit page with UserUnit 2 measures 612 × 792 points, or US Letter. Individual coordinates and scaled dimensions are bounded to a magnitude of one billion; degenerate boxes and unsupported values stop inspection rather than producing misleading measurements.
Visible size uses the intersection of CropBox and MediaBox, then applies UserUnit and quarter-turn rotation. A rotation of 90 or 270 degrees swaps displayed width and height. Negative equivalent rotations are normalized; unsupported non-quarter-turn values are rejected. Empty box intersections are errors. Raw auxiliary boxes are reported without silently clipping their dimensions, and boxes extending beyond the crop are flagged. This is a geometry report, not a simulation of every PDF viewer’s error-recovery behavior.
Switch the displayed measurements among millimetres, inches and points. Downloads always include complete numerical values, all pages, box provenance and warnings; the selected details page does not restrict the report. Size groups round visible widths and heights to 0.01 point. Therefore very small differences can fall into the same group, and portrait versus landscape dimensions form separate groups. Paper-name matching recognizes A3, A4, A5, US Letter, US Legal and Tabloid within one point per edge, regardless of orientation. Other sizes are labelled Custom / unlisted. A suggested name is not a statement of exact standards compliance.
For example, a PDF with one unrotated 612 × 792-point page and one 90-degree-rotated page of the same stored size reports visible dimensions 612 × 792 and 792 × 612 points. Both match US Letter, but they form different visible-size groups. Cropped pages can have smaller visible dimensions than their physical MediaBox.
The tool does not inspect text bounds, font embedding, image resolution, content clipping, printer margins, signatures, accessibility or PDF/X compliance. A valid geometry report is not print certification, and physical page numbers are not logical page labels. Use Resize PDF Pages if you need a separate changed-size PDF, or Crop PDF Pages if you deliberately want a different visible crop. This checker never rewrites the source.
Report downloads contain geometry but omit the original filename, text, author, document title and file fingerprint. Geometry can still be sensitive in context; review it before sharing. File contents stay in the local worker and are not uploaded by this tool.
Worked example: Distinguish stored size from rotated visible size
- Input
- Page 1: MediaBox [0,0,612,792], rotation 0°, UserUnit 1 Page 2: MediaBox [0,0,612,792], rotation 90°, UserUnit 1 No explicit CropBox
- Result
- Page 1: 612 × 792 pt · US Letter · portrait Page 2: 792 × 612 pt · US Letter · landscape 2 visible size groups; CropBox defaults to MediaBox
Box dimensions themselves do not rotate. Displayed visible dimensions do.
Common use cases
- Finding a mismatched paper size before a combined print job
- Checking whether crop dimensions differ from the physical page
- Exporting an all-page geometry inventory for a document handoff
- Distinguishing explicit print boxes from inherited or default values
Frequently asked questions
Does this change or resize the PDF?＋
No. It only reads geometry and creates a JSON or CSV report. Use Resize PDF Pages when you want a separate PDF with new page dimensions.
Why do CropBox and MediaBox give different sizes?＋
MediaBox defines the physical page boundary; CropBox limits the displayed or printed region. The checker intersects them for visible size and also reports their raw individual geometry.
What does default CropBox or TrimBox mean?＋
An absent CropBox defaults to MediaBox, while absent TrimBox, BleedBox and ArtBox default to CropBox. The report labels defaults so they are not mistaken for explicitly authored print settings.
Does a 90-degree rotation change stored page dimensions?＋
It changes displayed orientation. The inspector swaps visible width and height for 90/270 degrees while retaining raw box coordinates and unrotated box dimensions.
Is this a PDF/X or print-quality checker?＋
No. Page geometry alone cannot establish content quality, bleed artwork, fonts, image sharpness, accessibility, signatures or compliance with a print standard.
How exact are size groups and paper names?＋
Groups round each visible edge to 0.01 point. Named paper sizes allow one point of tolerance per edge. Full numerical dimensions remain in the downloads; a name match is approximate.
Related tools
Resize PDF Pages
Fit PDF pages to A4, Letter or custom sizes locally, with centered content and clear margins.
Crop PDF Pages
Trim visible PDF margins locally. Cropping hides content; it does not redact it.
Rotate PDF
Preview and rotate all, odd, even or selected PDF pages, then download the corrected file locally.
PDF Metadata Editor & Remover
Inspect, edit or remove PDF document properties and the XMP metadata packet locally in your browser.