If you like these browsers but are not able to download more RAM due to the coronavirus pandemic and global financial crisis, here's what you can do.

Chrome
  • Use the following command-line parameters.
    Code:
    --process-per-site --in-process-gpu --disable-breakpad --disable-crashpad --load-media-router-component-extension=0
    Note that they must be added to all shortcuts, as well as the association for HTML files and the HTTP and HTTPS protocols in the registry. None of these can be applied via group policy, so this is the only way. (If Chrome doesn't start after this, remove --in-process-gpu. If you really need Chromecast, remove the last one.)
  • Go to chrome://flags/#network-service-in-process, locate "Runs network-service in-process", set to enabled and restart.
  • Most extensions start an additional process and/or increase memory usage. Lose the ones you don't really need - I don't use any! As a prominent member here once said, "by eliminating the irrelevant, only the relevant remains".

Firefox
  • Options -> Preferences -> General -> Performance, untick "Use recommended performance settings", set "Content process limit" to 1 and restart.
  • Setting the environment variable MOZ_FORCE_DISABLE_E10S=1 will take that even farther by using just one process for everything, but is unsupported and may cause trouble.
  • Fewer addons = less memory usage.