To speed up mouse scrolling speed in Firefox in Linux Mint. This also works in Pale Moon browser. Also makes scrolling smoother and less jumpy. (This also works in other Ubuntu based distros.) In the Firefox URL field type, about:config and press Enter. In the Search field type, mouse Double-click on... mousewheel_system_scroll_override_on_root_content.enabled, default, boolean, false to toggle it to true. The line will now be displayed as: mousewheel_system_scroll_override_on_root_content.enabled, user set , boolean, true Click on the Firefox top menu Edit, Preferences, Click on Advanced, General Make sure [X] Use Smooth Scrolling is checked. This speeds up my mouse scrolling considerably in Firefox.