about:config dom.storage.enabled false browser.low_commit_space_threshold_mb 2/3 of total memory available in your system. free --mebi 3683 is 2455 cmdline systemd.unified_cgroup_hierarchy=1 (enabled by default by now ) and swapaccount=1 systemd-run --unit = my-firefox --user --scope -p MemoryHigh = 2.5G -p MemoryMax = 2.5G -p MemorySwapMax = 0 firefox %U systemctl --user show my-firefox.scope | grep Memory if firefox crash and cant run again clean systemctl reset-failed my-firefox.scope src: https://dev.to/msugakov/taking-firefox-memory-usage-under-control-on-linux-4b02
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