Hello pary,

Would you please take a look at this add-on and see if maybe it will do what you want :

https://addons.mozilla.org/en-US/firefox/addon/simple-tab-groups/

Any good, or does it not even come close to what you are looking for  ?

Hi pary, I know not everyone likes the following method, but maybe it will work for you:

Group Tabs into Different Windows

One way to organize related tabs into a group is to move them to a new window. In Firefox 64+ (you should get the update within the next 7 days), tab multi-selection is enabled. So you can view one of the tabs you want to group, then Ctrl+click the other tabs, then right click any one of them and choose

Move Tabs > Move to New Window

I usually have 5-8 windows open for different projects.

Now... I should mention that if you let the system close Firefox for you instead of using Exit from the menu, it may be impossible to restore all your windows. By default, you will get 3 back. To increase the number of closed windows that Firefox remembers, you can change a setting here:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste UNDO and pause while the list is filtered

(3) Double-click the browser.sessionstore.max_windows_undo preference to display a dialog where you can enter the desired value -- I use 10 -- then click OK

To restore a closed window, you can use any of these:

• "3-bar" menu button > Library > History > Recently Closed Windows
• "Library" toolbar button > History > Recently Closed Windows
• (menu bar) History > Recently Closed Windows