Setup DNS over HTTPS (DOH) in a Firefox browser, on an Android device for privacy and security.

Configuration Editor on Firefox⌗

Firefox on an Android device currently does not support setting up DNS over HTTPS (DOH) under the settings menu. However, as a workaround, it can be configured through Configuration Editor for Firefox.

Access it using the about:config keywords in the address bar of the browser. It is available only in beta and nightly versions of Firefox.

This setup also works on other variants of Firefox, for example, Focus and Mull.

Update the configuration related to Trusted Recursive Resolver(TRR).

  • network.trr.mode = 3

I set it to 3 instead of 2 as there is no way to know when the connection falls back when in mode 2.

If this is not set, Firefox uses Cloudflare DNS as the default provider. I set it to AdGuard DNS mainly to block ads and trackers. AdGuard has a test page to check if their DNS is configured correctly and working.