+++
date    = "2025-03-08T20:20:10+00:00"
lastmod = "2025-03-08T20:20:10+00:00"
tags    = [ "linux" ]
+++

To quiet down Firefox's network activity at the application level:

Set global (`about:policies`) [policies](https://mozilla.github.io/policy-templates/) in
[`/etc/firefox/policies/policies.json`](https://www.abcdesktop.io/common/disable-firefox-connections/#example-of-policiesjson-file)

Block untrusted connections with
[`proxy.pac`](https://www.abcdesktop.io/common/disable-firefox-connections/#sources)
[[?](https://developer.mozilla.org/en-US/docs/Web/HTTP/Proxy_servers_and_tunneling/Proxy_Auto-Configuration_PAC_file)]
in `policies.json`. Enable the {{< abbr PAC "Proxy Auto-Configuration" >}}
_file_ {{< abbr URL "uniform resource locator" >}} in (`about:settings`) network settings.

Additionally [user.js](https://kb.mozillazine.org/User.js_file) is configurable
([mine](https://github.com/tdro/dotfiles/blob/a0660d25ee6ce4152234320b26622495420e1c26/.config/.mozilla/firefox/profile.default/user.js)).
Firefox [derivatives](https://en.wikipedia.org/wiki/Category:Web_browsers_based_on_Firefox)
do similar [pre-configurations](https://www.abcdesktop.io/common/disable-firefox-connections/#usage-of-autoconfigjs-and-firefoxcfg). Chromium derivatives have
[policy settings](https://www.chromium.org/administrators/policy-templates/)
too.