Setting up Firefox with Tor on Linux


This guide assumes you have completed setting up Tor for Linux. Please visit this section first before you proceed as it is required for Firefox to properly work with Tor.

  1. Open Firefox.

  2. Enter about:config in the URL bar. Accept any warnings that may appear about accessing advanced settings.

  3. Search for dom.securecontext.whitelist_onions and set the value to true.

    Firefox whitelist onions screenshot
  4. In order to tell Firefox which urls to use Tor for, you need a Proxy Auto Config file. We have one hosted here. To get it, you can run:

    sudo wget -P /etc/tor
  5. Now open your Firefox web browser, and select preferences:

    Firefox preferences screenshot

    Select Settings ‣ Preferences

  6. Search for the term “proxy” in the search bar in the upper right, then select the button that says Settings…:

    Firefox search screenshot
  7. This should open a menu that will allow you to configure your proxy settings. Select Automatic proxy configuration URL and paste in:

  8. Check the box labeled Proxy DNS when using SOCKS v5:

    Firefox proxy settings screenshot
  9. Click OK and then restart Firefox for the changes to take effect.

  10. You’re all set!

You should now be able to navigate to .onion URLs in Firefox. This means you can bookmark Cups Messenger, and use your Bitwarden Tor address in the Bitwarden Firefox Plugin.