In Firefox, if you type any keyword in the address bar (also called URL bar) and don’t select any suggestions from the awesome bar before pressing Enter, you will be taken directly to the Google search result page. Even though users can change the search engine of the search bar (which is located next to address bar), there is no build-in option to change the search engine of the address bar as well. The address bar search engine is controlled by the variable “keyword.url” in about:config. Change the value to “https://www.bing.com/search?q=” as shown in the screenshot below and you will see all searches redirecting you to Bing.
To revert back to Google, simply change the variable back to “https://www.google.com/search?ie=UTF-8&oe=UTF-8&sourceid=navclient&gfns=1&q=” A small but useful tip for all those who are using Bing as their default search engine of choice.