For some unknown reasons, Mozilla has removed "Save and Quit" feature from Firefox 4.0 and later versions. In earlier versions, if you opened more than one tabs in Firefox and clicked on Close button, it used to show a dialog box to save your tabs and quit the window.

In Firefox 4.0 and later versions, it no longer allows you to save the tabs. Whenever you click on Close button, it only warns you with a dialog box but doesn't provide any button to save the tabs.

Using this small trick, you can bring back the good old feature in Mozilla Firefox 4.0 and later versions:
1. Open Firefox and type about:config in the addressbar and press Enter. It'll confirm, click on I'll be careful, I promise! button.

2. Now type quitwarning in the Filter box, it'll show following boolean key:
browser.showQuitWarning
3. The entry "browser.showQuitWarning" would be set to false. Double-click on it or right-click on it and select toggle. It'll set its value to true.
4. Now whenever you close multiple tabs, Firefox will ask you to save the tabs and quit.
Posted by: Vishal Gupta | Categories: Mozilla Firefox
del
Much thanks great to get save tabs back on close, appreciated
Carmen
I have tried to activate the safe tab feature back on my browser and "browser.showQuitWarning" option is not there for me to click on and change to true.
I am surprised this has changed today, yesterday was fine.I have Firefox ver. 3.6.17. I have not downloaded Version 4. What else can I do to try to get the Save Tabs and Quit feature back on?
VG
^^ Try to manually create it.
otock
thank for sharing, it's works
fe
does not work (anymore9
VG
^^ It works even in latest Nightly build.
Grateful Person
I use Firefox 15.0.1, used your steps and it immediately worked..many thanks my man..may you continue with your work, helping people like me.. Thank you
Moira
It worked. Thank you, thank you, thank you!!!
Tanvir
Thanks for the nice tutorial
Salvo
Excellent tip, it worked for me!
Selah
Thank you, this is very helpful!!!!!!! Works very well. :)
thanx
AWSOME
Thanx VG
worked GREAT
ftfr4nk
You are awesome!
Thank you!
Asma
Thanks a lot for this great help.
HelP L.N.E.
THANK YOU, THANK YOU, THANK YOU x 10000000000000000000000000000000000000000000000000!!!