This document explains all of the optionspreferences available in the Tabs panel of the OptionsPreferences window of Mozilla Firefox. To access the optionspreferences window, At the top of the Firefox windowOn the menu bar, click on the ToolsFirefoxEdit menu, and select Options...Preferences....
For other panels, see OptionsPreferences window.

The Tabs panel contains optionspreferences related to the tabbed browsing feature.

• Warn me when closing multiple tabs: When you close a window with multiple tabs, Firefox will ask you to confirm your choice. This prevents you from accidentally closing the whole window when you intended to only close the current tab. Uncheck this optionpreference to disable this warning and have Firefox automatically close the window.
• Warn me when opening multiple tabs might slow down Firefox: When you open a large number of tabs at once, Firefox will ask you to confirm your choice. This prevents you from accidentally slowing down your system while the pages are loading. Uncheck this optionpreference to disable this warning.
• Always show the tab bar: If you're only viewing one web page in a Firefox window, the tab bar is not normally shown. Check this optionpreference to always show the tab bar, including when only the Firefox window contains only one page.
• When I open a link in a new tab, switch to it immediately: When you middle-click on a Web link (or hold down CtrlCmd while clicking with the left mouse button), the page will be opened in a new tab. That page will not be displayed and will load in a background tab. Check this optionpreference to load and display the page in a new foreground tab instead.