How our leak tests work
The IP, DNS and WebRTC tests each measure a different layer of what your network
reveals. The IP lookup reads the address every site already sees. The DNS test uses our own
name server to reveal which resolver handles your lookups. The WebRTC test checks whether your
browser hands out addresses that see around a VPN, using only our own STUN server so nothing
goes to a third party. Full method and sources are on the about page.