NAT64Check is a tool developed by the Internet Society in collaboration with Stichting IPv6 Nederland, Go6, SJM Steffann, Internetbureau Max and Simply Understand. This allows you to enter the URL of a particular website, and then run tests over IPv4, IPv6 and NAT64 in order to check whether the website is actually reachable in each case, whether identical web pages are returned, and whether all the resources such as images, stylesheets and scripts load correctly. It also compares responsiveness using the different protocols, therefore allowing network and system administrators to easily identify anything is ‘broken’, to pinpoint where any non-IPv6 compatible elements need to be fixed.