Task Manager shows 11 Firefox running
I had 9 Firefox applications running in my Task Manager which was taking up too much memory (over 50%)
I came across this topic and solution here and reduced the processes in the settings from 8 to 5.
Instead of reducing the number of processes - as stated in your reply - they have increased to 11 with only 2 tabs open.
Any idea what is going on here, and how can I REDUCE the number of Firefox processes?
Every extension you use gets its own process. Please check that you do not have many extensions installed, and if you no longer need any, please get rid of them. Also note that there are a few builtin extensions.
I have only one extension.
So that's 3 processes. what about the other 8 out 11?
what builtin extensions do I have and where can I see them?
It is quite normal to see more Firefox processes running.
- process for the main Firefox thread (user interface)
- one or more content processes, see:
Settings (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 and about:processes pages for information about the process IDs.