multiple instances of firefox, but should only be one..
I discovered this issue this evening, no idea how long it's been going on. I opened Task Manager to see if a program was running (not firefox) . Firefox WAS open, and I had one window open in firefox.. BUT next to Firefox, was (7) so I expanded. It showed 7 instances. With only 2 programs open, (firefox and task Manager) the amount of memory it was using was surprising.. Using 64 bit version of Firefox, 86.0
I tried "ending task" on the instances that were using 0% CPU, but I was only able to close 2-3 before ALL of them closed. I would then reopen and it would be 6, 7, or 8 instances I tried 3 times.
Can someone enlighten me as to why it is doing this?
It is quite normal to see more Firefox processes running.
- process for the main Firefox thread (user interface)
- one or more content processes, see:
Options/Preferences -> General -> Performance
remove checkmark: [ ] "Use recommended performance settings"
- process for the compositor thread
- process for extensions
- process for WebRender when this feature is enabled
You can find the current multi-process state on the Troubleshooting Information page (about:support).
- "Help -> Troubleshooting Information"
"Application Basics": Multiprocess Windows
"Remote Processes" further down
See also the about:memory page for information about the process IDs.
Firefox is a multi-process application. The browser uses 1-4 processes for shared/overhead code, and there may be anywhere from 1-8 processes for tabs (content processes). Multiple processes are used for isolation, improved stability, and to execute web content with reduced privileges (sandboxing feature). Mostly likely, these processes are all part of the same instance of Firefox and would all close if you were to exit Firefox (one or two may take much longer than the others to shut down).