What is a MediaBox?

A PDF describes the content and appearance of one or more pages and also defines the physical size of those pages. There can be up to five different definitions in a PDF related to page size: MediaBox, CropBox, BleedBox, TrimBox and ArtBox. These are called the page boxes or boundary boxes. PDF boxes describe the page geometry of a PDF. They are used frequently in the printing industry.

The MediaBox

For the average user, the MediaBox is the actual page size. It defines the page width and height and represents what the user would see when printing the PDF page. It is less important for an interactive document displayed on screen, but it is very important for page geometry.

The PDF MediaBox describes the full area of the medium on which the page is printed. This includes any extra area outside the final page used for printer marks, bleed, etc. The MediaBox contains all the other boxes in the PDF, making it the largest box. It is the only box that is strictly required. If the other boxes are not defined, they are the same size as the MediaBox.

Find out more about the other PDF boxes in the following article.