The userChrome.css file does not exist by default, so once you have a tweak or two you want to try out, you first have to create the file in the appropriate location inside your Firefox profile folder. This will provide the information you need to customize various browser interface elements with your own CSS code. If you know what you’re doing with CSS, you can enable the browser toolbox to inspect the Firefox browser’s chrome. Older userChrome.css tweaks you find online may not function on Firefox 57 and later, also known as Firefox Quantum.
#CURRENT VERSION OF FIREFOX USES CSSX HOW TO#
If you want to make a certain change, someone else has probably already figured out how to do it and written the code.
#CURRENT VERSION OF FIREFOX USES CSSX CODE#
While you could create your own tweaks if you understand CSS code and how Firefox’s interface was designed, you can also just find tweaks online. Many tweaks that could previously be accomplished by browser add-ons can now only be accomplished by editing the userChrome.css file. The userChrome.css file has existed in Firefox for a long time, but it’s taken on renewed importance with Firefox Quantum. “Chrome” refers to the user interface of the web browser, which is what Google Chrome was named after.
This has nothing to do with Google Chrome. You can’t actually add any features you can only modify what’s already there to change, hide, or move it. It allows you to change the appearance and layout of everything surrounding the webpage iteslf. While style sheets are normally applied to web pages, this particular style sheet is applied to Firefox’s user interface. RELATED: Firefox Quantum Isn't Just "Copying" Chrome: It's Much More Powerfulįirefox’s userChrome.css file is a cascading style sheet (CSS) file that Firefox uses.