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My Task manager shows 6 firefox.exe, what should I do?

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  • Last reply by cor-el

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My computer is running slow, so I went to Task Manager, and discovered 6 Firefox.exe listed. Why would that be? should I get rid of some of them?

My computer is running slow, so I went to Task Manager, and discovered 6 Firefox.exe listed. Why would that be? should I get rid of some of them?

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More than one process is normal for the current Firefox. http://www.ghacks.net/2016/07/22/multi-process-firefox/

Multi-process Firefox is codenamed "e10s". https://wiki.mozilla.org/Firefox/multiprocess

Try to disable multi-process tabs in Firefox. You can disable multi-process tabs in Firefox by setting the related prefs to false on the about:config page.

browser.tabs.remote.autostart = false browser.tabs.remote.autostart.2 = false

Type about:config<enter> in the address bar. If a warning screen comes up, press the I Accept the Risk button. At the top of the screen is a search bar.

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You can first try to limit the number of content processes to 1.


You may see three or more Firefox processes running.

  • one process for the main Firefox thread (user interface)
  • one or more content processes set via dom.ipc.processCount
    Options/Preferences -> General -> Performance
    remove checkmark: [ ] "Use recommended performance settings"
  • one process for the compositor thread (Windows;graphics)

You can find the current multi-process state on the Troubleshooting Information (about:support) page.

  • "Help -> Troubleshooting Information" -> "Application Basics":
    Multiprocess Windows
    Web Content Processes