Place a checkmark next to the Confirm before closing multiple tabs option.Open the General section and scroll down the list of options to the Tabs part.Open the browser and click the menu button with three lines in the upper-right hand corner of the window.
Here is how to enable the Close Tab confirmation in Firefox 94 and onward. Still, Mozilla allows users to restore the Close Tab warning prompt. For that reason, Firefox developers decided to keep the Close Tab confirmation message on macOS and Linux. Mozilla says the risk of accidental closure is higher on those platforms because the quit app shortcut ( Cmd + Q on macOS, Ctrl + Q on Linux) is adjacent to the application switch shortcut ( Cmd + Tab). Interestingly, the Close Tab confirmation message remains on by default on macOS and Linux. That is no longer a case because Mozilla thinks the prompt 'provides unnecessary and perhaps unwelcome friction.' Before Mozilla Shipped Firefox 94, the browser would show a warning message when users tried to exit Firefox with numerous tabs open.
