Mozilla’s Firefox web browser tests on startup whether the network connection being used requires a connection; this is common when a device is connected to a public hotspot, such as when using a hotel’s wireless connection.
While this is useful in some cases, it’s not something that many Firefox installs need. If you only use Firefox at home, you do not need the verification to be performed. This reduces automatic connections made by the browser and can also speed up startup a bit.
Firefox tries to connect to http://detectportal.firefox.com/success.txt during the test to see if it can connect to the address. The same address is also used to test if the active network connection supports IPv6.
To note: You may need to revert changes if you notice connectivity issues; it shouldn’t be, but it’s easy to undo if something goes wrong.
Disable Firefox network connectivity tests
- Load about:config into the Firefox address bar to get started.
- Confirm the “Accept the risk and continue” prompt that appears. You can also uncheck “warn me when I try to access these preferences” to skip the prompt next time.
- Find preference network.captive-portal-service.enabled using the search box at the top.
- Set the preference to FAKE by clicking the toggle icon on the right. To cancel the change, repeat the action so that the preference value is TRUE.
- Find preference network.connectivity-service.enabled using the same method as described above.
- Set the preference to FAKE by clicking the toggle icon. To undo the change, repeat the action so that the preference value is set to TRUE again.
The network.captive-portal-service.enabled preference checks whether the network connection requires authentication. Firefox users who travel a lot and those who connect to networks that require authentication may want to keep the default value of the TRUE preference. Anyone can set it to FALSE without experiencing usability or connectivity issues.
The network.connectivity-service.enabled preference determines the capabilities of the network connection by connecting to the same address as network.captive-portal-service.enabled.
The Tor Project has disabled the feature in its browser, with no reported issues since the change. The development team noted that Firefox establishes this connection whenever the network state changes:
NetworkConnectivityService probes http://detectportal.firefox.com/success.txt?ipv4 and http://detectportal.firefox.com/success.txt?ipv6 whenever the network status changes (network:link-status- event changed). We should probably disable it unless it’s needed for browser functionality.
Most Firefox users don’t need both preferences when using the browser. Some users may want to do this for privacy reasons, others to reduce the number of connections made by the browser.
Now you: Do you monitor your browser’s automatic connections?