Recently, I needed to use Firefox in full screen mode, but ran into an annoyance you might have seen. While the presentation was nice, seeing the web page stretch across my entire monitor when I hit the F11 key, I did not want the address bar and tab bar to disappear.
So, now the question I needed to answer is how can I always show the navigation toolbar and the tabs toolbar when browsing in full screen mode in Firefox?
The answer was simple, and probably overlooked by many. When in full screen mode, simply right-click the navigation toolbar and un-check “Hide Toolbars”.
That is all you need to do. There is no need for an about:config tweak or add-on to download. Just an often overlooked and simple solution to a Firefox browsing preference. Hope this comes in handy for all of you out there. It just goes to show you sometimes the most simple Firefox fixes are right under your nose.