What a WebRTC leak is
WebRTC lets browsers make video calls and file transfers directly between devices. To connect, the browser asks STUN servers for its public address. With some VPN setups, that request goes outside the VPN tunnel, and a website can read your real IP address even though the VPN hides it everywhere else. That is a WebRTC leak.
How this test works
- Our server returns the IP address your connection uses, as on the what is my IP page.
- Your browser gathers its WebRTC candidates for up to 5 seconds.
- We compare the public addresses found by WebRTC with the one our server sees.
To discover your public address, the browser contacts public STUN servers run by Cloudflare and Google. Nothing is sent to our server except the normal request that shows the IP it sees.
How to read the result
| Result | Meaning |
|---|---|
| Same public IP | No leak: WebRTC shows the address your connection already uses. |
| Different public IP | Possible leak. With a VPN on, this may be your real address. |
| No public IP | WebRTC revealed nothing public: no leak. |
| WebRTC blocked | Your browser or an extension disables WebRTC: no leak possible, but video calls in the browser may not work. |
Local addresses (192.168.x.x, 10.x.x.x) are private and harmless; recent browsers hide them behind random ".local" names anyway.
How to fix a leak
- Turn on your VPN app's WebRTC leak protection if it has one.
- In Firefox, set `media.peerconnection.enabled` to false in about:config (this also disables browser video calls).
- Use a VPN that routes all traffic, including UDP, through the tunnel.
Frequently asked questions
Does a WebRTC leak matter without a VPN?
No. Without a VPN, every website already sees your public IP. The leak only matters when you rely on a VPN or proxy to hide it.
Is IPv6 a common source of leaks?
Yes. Some VPNs only tunnel IPv4. If WebRTC shows an IPv6 address from your provider while the VPN is on, enable the VPN's IPv6 protection or disable IPv6.
Why does the test say WebRTC is blocked?
Some browsers, privacy extensions and company networks disable WebRTC. That prevents leaks, but also browser-based video calls.