Don’t forget keyboard navigation

Many developers take for granted that everybody uses a mouse to interact with the web. I don’t have any numbers, but it is indeed likely that the majority of people are primarily mouse users.

However, some people choose not to use a mouse because they find using the keyboard to navigate is faster. Others simply cannot use a mouse and are forced to use other input devices.

Either way, accommodating people who do not use a mouse is not very difficult:

Make sure that all interactive objects can be activated by the keyboard alone
Use the :focus CSS pseudo-class to highlight elements when they receive focus

Testing how you’re doing is easy—just unplug your mouse and try using the site you’re working on.