Please Copy/Paste about:preferences#search into the Address Bar and press Enter So what is not working here. In the drop down Search for me it says Change Search Settings which again takes you to the above page to Add place a tick mark beside the search engine you want to show up in the drop down menu, Remove un-tick it or if never want to see again Delete It. Please let us know if this solved your issue or if need further assistance. If you have not found it yet Click the 3 Dots in the Address Bar for Tools If not Found it yet Click the 3 Bar Menu far right top then Customize. Put them where you want to. https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/ and Here's a more comprehensive project which affects not only tabs but brings back the old "grid-style" options menu. https://github.com/axydavid/FirefoxUI/blob/master/README.md It isn't completely possible to use the Australis design with Firefox 57, but depending on what you want, you might be able to customize the UI to look more like the old one: This project: https://github.com/wilfredwee/photon-australis lets you have the old tab bar appearance back in Firefox 57. You can remove the space around the address bar by right-clicking on the spaces, and choosing "remove from toolbar". Note the Black Theme is just a Example and can be found in Customize. Please let us know if this solved your issue or if need further assistance.

Hi ! In addition to the above : In Options => Search, under 'Search Bar' - have you checked : 'Add search bar in toolbar' ? See screenshot :