''eloiman [[#question-1142685|said]]'' <blockquote> I enable Firefox Sync a couple of days ago. It works somehow but I think it works wrong as I don't see all my tabs in the synced list which I think should be present there. I run sync on my Firefox 49.0 Linux with several windows which, in turn, are opened in several linux workspaces. I think Firefox Sync was seems to be only processed 3 my opened windows on the current workspace. So I don't see the contents of all Firefox windows from several workspaces on my another Firefox >45.0 windows. I would like to check which tabs are went to the sync list, so I want to see the list of all tabs which are synced including the current device. How can I see the list of the tabs which are synced from the current device? (and all tabs from all other my devices as well). </blockquote> I have got an idea how it works and it's sucks! Firefox looks for your activity between Sync sessions and it only puts the tabs you touch (between syncing sessions) to the Syncing list. I suppose It is not obvious behavior as I expected all tabs (and all staff which are checked in the settings) must be synchronized. Could anybody from Mozilla fix it? I have about 300 tabs opened, I like them to be synchronized among all my devices with Firefox Sync as this feature offers such service initially.