Setting up Firefox with Tor on Desktop

Warning

This guide assumes you have completed setting up Tor. 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. Download a Proxy Auto Config file to inform Firefox how to use the Tor daemon running on your computer. You can get Start9’s standard file by following the OS-specific instructions below:

    Windows:

    Click here to get the file and save the file somewhere you won’t delete it. Please remember the location you save the file in if you do not use our example location. For this example:

    C:\Program Files\Tor Browser\proxy.pac
    

    Mac:

    Open the Terminal App on your Mac. You can find it in your list of Applications. In the terminal, enter:

    brew install wget
    

    And then:

    wget -P /usr/local/etc/tor https://registry.start9labs.com/sys/proxy.pac
    

    Linux:

    From a terminal, enter:

    sudo wget -P /etc/tor https://registry.start9labs.com/sys/proxy.pac
    
  5. Now open your Firefox web browser, and select options (Windows), or preferences (Mac/Linux):

    Firefox options screenshot

    Select :menuselection:Settings --> Options

  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 the path to your PAC file from earlier, prefixed with file://. For example:

    Windows:

    file://C:/Program Files/Tor Browser/proxy.pac
    

    Mac:

    file:///usr/local/etc/tor/proxy.pac
    

    Linux:

    file:///etc/tor/proxy.pac
    
  8. Then, 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.