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FirefoxCP WebExtensions and FireFoxCP Isolated Web Content

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  • 1 has this problem
  • Last reply by cor-el

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FirefoxCP WebExtensions and FireFoxCP Isolated Web Content seem to cause my Mac's fans to spin crazily and are taking up the most resources by far. This happens most frequently on Hearst newspaper site and other heavy ad sites. I can turn off Enhance Tracking Protection which does not really seem to have an effect. I mean the fans will slow after about a minute or two and then start up again when I go do the next page. According to Mac Activity Monitor FirefoxCP WebExtensions will use up just over 2GB of memory and FireFoxCP Isolated Web Content will use just under 2GB of memory.

FF 94.0.2 (64-bit)

macOS Monterey 12.0.1 MacBook Air (13-inch, Early 2015) 2.2 GHz Dual-Core Intel Core i7 8 GB 1600 MHz DDR3 Intel HD Graphics 6000 1536 MB

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You may have Fission enabled. Fission is about a new site isolation architecture in Firefox and you will see more Firefox processes running than before and when Fission is enabled you can no longer limit the number of content processes in Settings or via dom.ipc.processCount on the about:config page. You can check the current Fission state on the "Help -> More Troubleshooting Information" (about:support) page (search for Fission).

You can disable Fission by setting fission.autostart = false on the about:config page. You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.


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