Firefox is one of the most popular browser used for web browsing today. Now your Firefox browser may be powered by either Google, Bing or Yahoo for searching queries. But you can set any search engine provider for your Firefox browser. At first let us find out what is the current search engine for Firefox.
Type any query in the address bar and hit enter.
As you can see the result above is provided by Google. Suppose if you want to change the search engine from Google to Bing then Click on the drop down button of the search box, located on the address bar of Firefox, as shown in the picture below.
Now again type any search query.
This is how you can change the search engine in Firefox from Google to Bing, Bing to Google and so on.