This article explains how to change the print page setup in the Firefox browser. Instructions apply to the Mozilla Firefox web browser on Windows, Mac OS X, macOS Sierra, and Linux operating systems.

First, open the Firefox browser. In the upper right corner, select Menu (three horizontal lines). When the pop-out menu appears, choose the Print option.

Firefox's Print Preview interface should now appear in a new window, allowing you to see what the active page will look like when sent to the designated printer or to a file.

At the top of this interface you will find several buttons and drop-down menus, including the ability to choose between Portrait or Landscape for the print orientation.