The Firefox profile manager is a built-in tool that can be used to create, edit and delete Firefox profiles. Each Firefox profile is independent from each other which means that it can have its own set of settings, bookmarks, extensions, plugins, interface and themes. It is for instance common to create multiple profiles for different usage scenarios, say web development and normal surfing or search engine optimization and secure browsing.

Firefox users can start the profile manager with the parameter -profilemanager. Additional information and instructions are available in the guide Working with several Firefox profiles.