Well.. I am using Windows 10. I see the PID process for Firefox is gone and not running when I close it. The network connections still show up in NETSTAT and they are now associated with PID 0 - 'System Idle Process'. Does Firefox have a setting to tell Windows not to wait and close the network connections immediately?

Hi Stan, could you check whether the website create a service worker to connect in the background? There is an internal page you can open using the address about:serviceworkers (paste that in the address bar and press Enter to load it). If you find it there, you can unregister it.

(I don't know whether there is a way to automatically unregister service workers when you close a site, if that is what needs to happen.)

Interesting but there are no 'serviceworkers' registered. I vaguely remember that at one time Firefox had an option in this regard - something like 'close all running processes on exit'. One would hope that the network connections would close too but this may be more of an issue with the way Windows works. I find it very odd that the network connections would still be listed in 'netstat -ano' even when the process (Firefox) has closed/terminated.

Oh, I misunderstood, I thought you were closing one site but not the entire browser. Service workers should not run if all instances of firefox.exe have terminated. Could you also check the Windows 10 Task Manager, Details tab, and confirm that there are no more firefox.exe processes running there 60 seconds after shutdown?

Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox Title bar.

• "3-bar" menu button -> Exit (Power button)
• Windows: File -> Exit
• Mac: Firefox -> Quit Firefox
• Linux: File -> Quit