What each leak is
DNS: the lookup that turns a website's name into an address. If it goes outside the tunnel to your provider's server, the provider can see which sites you look up, even with the VPN on. The test resolves dozens of random names and shows which DNS servers made the lookups.
IPv6: the newer version of the IP address. If a VPN only handles IPv4, IPv6 traffic can go straight out over your provider's network, with your real address.
WebRTC: the browser feature for video and audio calls. RFC 8828, from the IETF, explains that with a VPN that splits traffic between the tunnel and the regular network, WebRTC can reveal the provider's public address as well as the VPN's.
How to run the test yourself
- Turn off any other VPN and, on iPhone or Mac, iCloud Private Relay. Otherwise the no-VPN round won't show your provider.
- With the VPN off, open browserleaks.com/ip, browserleaks.com/dns (and run the DNS test) and browserleaks.com/webrtc. Note which provider appears.
- Turn the VPN on and open the same three pages.
- A leak is your provider showing up with the VPN on: in the IP address, in the list of DNS servers, in IPv6 or in the WebRTC public IP. A private IP such as 192.168.x.x in WebRTC isn't your public IP.
- If IPv6 doesn't show up even without the VPN, the IPv6 test doesn't apply to your network.
What about FortiSafe?
FortiSafe uses WireGuard and sends all of the device's traffic through the tunnel, including IPv6.
DNS protection is chosen on each device: no filter, scams, or scams and adult content. The default is no filter.
The kill switch, which blocks the internet if the VPN drops, is also in development.
Sources
Pages checked on 14 September 2026.
- BrowserLeaks — DNS leak test — How the test works: 50 random names, 25 IPv4-only and 25 IPv6-only.
- BrowserLeaks — IP address and IPv6 — The IPv4 and IPv6 addresses websites see.
- BrowserLeaks — WebRTC leak test — Public and local IPs revealed by WebRTC.
- IETF — RFC 8828, WebRTC IP address handling — Why WebRTC can reveal the provider's address with a split-tunnel VPN.
- Apple — About iCloud Private Relay — What Private Relay does with your IP address and DNS in Safari.