SixOrNot by Ashley Baldock

Version 3.3.0 (for Firefox 63+) returns DNS lookup information to SixOrNot, alongside TRR status and TLS information for connections.

With the forthcoming changes in Firefox 60 to support DNS lookup I've decided to update SixOrNot using the WebExtensions API. 3.0 does drop some functionality (like local address display) which is sadly not possible in the world of WebExtensions.


See at a glance whether websites support IPv6, with additional information about each domain contacted to display the current page. Now also shows proxy use, TLS information per-host and Trusted Recursive Resolver (TRR) status for connections.

• Information comes from both the DNS entries of the servers contacted to load page elements and from the connections Firefox makes to those servers - providing the most complete information possible.
• The icon can be shown either in the address bar or as a toolbar button (which can be customized to many locations in the Firefox interface).
• This addon does not consult with any external service to determine IP addresses, making use of local built-in DNS resolution methods, avoiding any privacy concerns arising from such behaviour.
• By looking at both the DNS entries for a domain and the IP version used to make connections to it SixOrNot can see when you are connecting via IPv4, but the remote site has the capability to be contacted via IPv6.
• DNS, TLS and IP address information can be copied to the clipboard by clicking on entries (v.3.3+)
• Shows information about proxies used to load page resources
• Shows information about Trusted Recursive Resolver (TRR) status for hosts