Despite Mozilla released Firefox 7 which uses low memory, thanks to Memshrink project, developers are releasing the extensions that save memory used by tabs in Firefox.
Few days back covered Dormancy add-on which automatically closes inactive tabs in Firefox after 5 minutes to free up memory of those tabs, now another developer came up with CleanupTabs Firefox add-on which automatically closes unused tabs and at the same time keeps the all the tabs you’ve recently viewed.
Know Which Firefox Add-on is Consuming More Memory
So there is a definite loss of unused tabs with this extension, but the gain is Firefox uses low memory, CleanupTabs offers the options to sort all tabs in most recently viewed order and to show tab numbers.
You can switch to N number tab using Ctrl + N shortcut, with the “show tab numbers” option enabled.
Set Max Number of Tabs to Open in a Window for Firefox with Max Tabs Add-on
If you don’t want to lose the tabs and at the same time want Firefox to consume low memory, you can use Memory Restart add-on which alerts when memory usage of Firefox reaches certain threshold limit and you can click on ‘Restart’ button to restart Firefox.