IPv4.2

ipv4.2.kasperd.dk

The linked website is ipv6 only. If it does not load you are probably using an ipv4 only ISP.

Also, it's an April 1st joke.

Archive will save you: https://archive.is/RAEu0 - if you're one of the people with high mental IPv6 adoption resistance.

shame that the audience it was intended for cannot read it.