--- title: "PDF Page Size Checker - Dimensions Online | CanDoYa" description: "Check PDF page size online in points, inches and millimetres. Find A4, Letter, mixed sizes, orientation and rotation privately in your browser." url: https://candoya.com/tools/pdf-page-size-detector/ locale: en type: browser-tool --- # PDF Page Size Checker Category: PDF ## What is a PDF page size checker? A PDF page size checker reads every page's visible dimensions and converts them into points, inches and millimetres. It identifies common paper formats such as A4 and US Letter, adjusts for page rotation, and flags mixed-size documents before they cause printing, binding or sharing problems. **PDF files describe page geometry with boxes, not a single page-size field.** This checker uses the CropBox that a viewer displays and compares it with the full MediaBox. The analysis runs locally, so confidential briefs, reports and print files never need to leave your device. The report groups pages by physical dimensions while keeping portrait and landscape orientation visible. That means a rotated A4 page still belongs to the A4 group, while a true Letter page creates a separate size group. ## How to use it 1. **Choose the PDF** - Drop one PDF into the checker or select it from your device. You can also load the mixed-size example. 2. **Review the summary** - See the page count, number of physical paper sizes, rotated pages and CropBox differences at a glance. 3. **Inspect every page** - Compare paper matches, orientation, rotation and exact dimensions in points, inches and millimetres. 4. **Keep the report** - Copy the readable report or download the page-by-page measurements as CSV. ## Who it's for - **Print designers** can confirm trim-facing dimensions and catch a Letter page hidden inside an A4 job. - **Office teams** can inspect reports assembled from scanners, exports and attachments before printing them as one document. - **Publishers and students** can verify page orientation and paper format before submitting books, theses or portfolios. - **Developers and QA teams** can export a CSV inventory for automated checks, bug reports or production handoffs. ## Expert note PDF rotation changes how a page appears without changing its stored box dimensions, so this checker swaps width and height for 90-degree and 270-degree rotations before deciding orientation or matching a paper size. ## Frequently asked questions ### Is my PDF uploaded? No. The PDF parser runs in your browser and reads page geometry directly on your device. The file is not sent to CanDoYa for processing, so the checker is suitable for confidential reports, client documents and unreleased print work. ### Is the PDF page size checker free? Yes. You can inspect every page, copy the report and download the CSV without creating an account or installing desktop software. The current file limit is 100 MB to keep browser memory use predictable. ### How do I check a PDF page size online? Choose or drop the PDF, then read the page-size report. Each row shows its paper match, orientation, rotation and width by height in points, inches and millimetres. A summary above the table tells you whether the document mixes physical page sizes. ### Why does a rotated PDF report swapped dimensions? A PDF stores page boxes separately from its rotation instruction. A 595 by 842 point A4 page rotated 90 degrees appears as 842 by 595 points. The checker reports that displayed orientation while preserving the stored geometry in the rotation details. ### What is the difference between CropBox and MediaBox? MediaBox is the full physical page boundary. CropBox is the region a PDF viewer clips and displays, and it defaults to MediaBox when no separate crop is set. This checker measures the displayed CropBox and flags pages where it differs from MediaBox. ### How are A4, Letter and other paper sizes detected? The checker compares the shorter and longer page edges with standard dimensions using a 2.5-point tolerance, about 0.88 mm. The tolerance accepts normal rounding in generated PDFs while keeping genuinely different page sizes in separate groups. ### Can it open a password-protected PDF? No. Encrypted PDFs must be unlocked before their page geometry can be read. If the checker detects password protection, it shows a specific message and leaves the file unchanged so you can unlock it with an authorized PDF tool and try again. ## Related tools - [PDF Page Counter](https://candoya.com/tools/pdf-page-counter/) - [Rotate PDF](https://candoya.com/tools/rotate-pdf/) - [Split PDF](https://candoya.com/tools/split-pdf/) - [PDF to Image](https://candoya.com/tools/pdf-to-image/) - [Image to PDF](https://candoya.com/tools/image-to-pdf/) --- *Markdown edition of , published for AI agents and other automated readers. Index of key pages: .*