If you are a Firefox user for long enough, you might remember the feature that lets you save the tabs when you try to close Firefox with multiple tabs. But for whatever reason, Mozilla thought that it is a good idea to disable this feature and show a simple warning message something like "You are closing multiple tabs." This warning message is not at all useful in any way. Sure Firefox settings allow you to save the session when you exit the application, but those settings don't allow you to choose whether you want to save the session or not on per session basis. So, if you are someone who likes the good old "Save and Quit" feature then here is how you can bring it back in Firefox.
Enable Save and Quit Feature in Firefox
Even though Firefox doesn't provide any "point and click" setting in the Settings panel, enabling the Save and Quit feature in Firefox is pretty easy. All you have to do is change a config setting. To do that, open your Firefox browser, type
about:config in the address bar and press the enter button on your keyboard.
The above action will open the Firefox Configuration page. This page may show you a warning message. Simply click on the button "I'll be Careful, I Promise" to see the main settings page.
Once you are in the settings page, search for the setting
browser.showQuitWarning using the search bar visible on top of the page.
After finding the setting, right-click on the value field and then select the option "Toggle." Alternatively, you can simply double click on the setting to toggle the value.
The above action will toggle the value from the False to True. Once you are done with the changes, this is how it looks like.
That's all there is to do. From this point forward, whenever you are trying to close multiple tabs, Firefox will ask whether you would like to "Save and Quit" or just quit without saving the current session.
In future, if you ever want to disable this feature, simply go through the procedure and toggle the value back to "False" and you are good to go.
Hopefully that helps and do comment below sharing your thoughts and experiences about using the above method to bring back Save and Quit feature when closing Firefox with multiple tabs opened.