Responsive designs adapt to different screen sizes to provide a presentation that is suitable for different kinds of devices, such as mobile phones or tablets. The Responsive Design View makes it easy to see how your website or web app will look on different screen sizes.
There are three ways to enable Responsive Design View mode:
- Select “Responsive Design View” from the Web Developer submenu in the Firefox Menu.
- Press the “Responsive Design View” button in the Toolbox’s toolbar.
- Press Ctrl + Shift + M.