Testing for DNS leaks is pretty similar to the previous leak test, just look at the DNS servers instead of the IP address:
1. Open browserleaks.com/ip while the VPN is disconnected and make a note of your DNS servers’ IP addresses (found in the ‘Your DNS Servers’ section). Unless you have changed your device’s DNS settings, the DNS servers shown will be those belonging to your ISP. You can see our DNS servers in the screenshot below.
DNS Results When Disconnected From the VPN
2. Connect to any server on the VPN server list. Then, refresh the leak test page on your browser.
3. Look at the DNS server results again. If any of your ISP’s DNS servers appear, your VPN is leaking DNS requests.
Here are two examples of DNS leak tests we ran while connected to two different VPNs.
The first is ExpressVPN – only one DNS server appears and it belongs to the VPN company. The DNS servers listed above in the first test are not showing, therefore it’s not leaking DNS requests.
DNS Results When Connected to ExpressVPN
The second is VPN99 – you can see both Google DNS and our ISP’s DNS servers. VPN99 uses Google DNS rather than first-party servers, however the presence of our ISP’s servers in the results shows that it’s leaking our DNS requests.
DNS Results When Connected to VPN99