Tool to know if you have DNS leaks, and another one for your ip leaks through the WebRTC protocol, useful if you use VPN.

Also two web sites where you can check the reliability of your ad blocker.

DNS Leak Test:
https://www.dnsleaktest.com

WebRTC Leak Test:
https://browserleaks.com/webrtc

AdBlock Test:
https://d3ward.github.io/toolz/adblock.html
https://adblock-tester.com