You will no longer receive a warning when attempting to close a Firefox window with multiple tabs open as of Firefox version 94. Fortunately, the feature has not been completely removed, and you can reactivate it through the Firefox settings menu.
When you close multiple tabs in Firefox, you will receive a warning.
- To re-enable the missing Firefox prompt, launch the browser on your Windows, Mac, Linux, or Chromebook computer.
- Click the three horizontal lines in the top-right corner of Firefox.
- Select “Settings” from the menu that appears.
- Click “General” in the left sidebar of the “Settings” window.
- Enable the “Confirm Before Closing Multiple Tabs” option on the “General” screen, in the “Tabs” section.
Tip: To again disable the prompt that appears when closing multiple tabs, turn off the “Confirm Before Closing Multiple Tabs” option.
And that’s the end of it. When you close a window with multiple tabs open in it, Firefox will now display a warning before closing the window.