Firefox has been constantly gaining ground as the go to web browser for many web designers and developers. Firefox’s most popular feature is the use of extensions to enhance the browsers capability beyond simple website viewing. For developers and designers this means being able to add tools to the browser to speed up their workflow by completing tasks while viewing work in the browser. Currently Mozilla has nearly 1000 plug-ins listed in the web development category for Firefox. Here we will focus on the most popular and useful Firefox extensions for web development and design.