In Firefox, users can use either the search bar or the address bar to perform a search, but now it is not like what it used to be. In the past, in older versions, users could set a different search engine for the address bar. But this capability has been removed since the release of Firefox 23. Now both the search bar and address bar share the same search engines, which is why there are many users, especially power users, don’t like this update.
While the keyword search feature—that makes you possible to use a custom search engine by typing a custom keyword in the address bar—is still available, you might still want to use the search box instead of completely removing it from the navigation bar.
Keyword Search is a restartless Firefox add-on specifically made to fix this. It brings back the old good feature to your Firefox browser. Additionally, it can also enable the Browse By Name & I’m Feeling Lucky search as well as I’m Feeling Ducky search of DuckDuckGo.
After you install it, a page is opened where you can change the default search engine for the address bar immediately by choosing one from the available options from the drop-down list.
If you want to change it to another engine someday, you can do it from the add-on’s option page. Pick one from the available items from the drop-down list of Keyword Search Engine.
You can also change the search engine used on Firefox default home or start page.
Note that the add-on also adds DuckDuckGo into the list of your Firefox search engines.
Version tested: Keyword Search 1.0.5 on Firefox 23 | Homepage