Free tool
WebRTC leak test
WebRTC is the browser feature behind video and voice calls. It can open connections that bypass a VPN tunnel, and this test checks whether yours is doing that.
This checks whether WebRTC, the browser feature behind video and voice calls, is reaching the internet outside your VPN tunnel and revealing an address your normal browsing doesn’t.
The result is worked out in your browser and never sent to us: we don’t log it, store it, or count it. The STUN server it contacts is our own, so no third party sees your address.
What a WebRTC leak actually is
To set up a call, WebRTC asks an external server what address your connection appears to come from. If that address is different from the one the rest of your browsing uses, WebRTC is reaching the internet outside your VPN, and a website could read your real address even though everything else is tunnelled.
That comparison is the whole test. We check the address WebRTC reports against the address we see your browser connecting from, and we only compare like with like: an IPv6 address is never compared against an IPv4 one, a mismatch that causes false alarms on some other leak tests.
Why “no leak” isn’t a gold star
Most modern browsers pass this test whether or not you use a VPN, because they hide your local network address by default. A pass mostly tells you your browser is behaving normally on this network, right now. It says nothing about DNS leaks, IPv6 outside WebRTC, or what happens when your connection drops and reconnects, which is exactly when leaks tend to appear. Re-run it after switching networks.
About that “local address” result
If the test says your local network address is visible, that isn’t a VPN failure. It’s the private address your device uses on your own network, and it doesn’t say who or where you are. It’s a fingerprinting signal worth closing, but it’s a browser setting, not something a VPN controls.
Protect the connection you just tested
DarkMatter encrypts your connection and hides your IP address from the sites you visit, with DNS and IPv6 leak protection designed to keep your traffic inside the tunnel.