DNS leak
When name lookups travel to your ISP’s resolver instead of through the tunnel, exposing every domain you visit.
Glossary
WebRTC leak
When a browser exposes your local or real address through the peer-connection API, independently of the VPN tunnel.
Why it matters
It happens in the browser, above the tunnel, so a perfectly configured VPN does not prevent it. Any site can trigger it with a few lines of JavaScript.
What most explanations leave out
This is a browser problem, not a VPN problem, which is why providers address it with an extension rather than in the client. If you are relying on the VPN app alone, the extension is not installed and the leak is available.
Related terms
IPv6 leak
When a tunnel carries only IPv4 while your connection also has IPv6, so IPv6-capable sites see your real address.
Referenced from
Terms are defined here because they appear in our scoring rubric or in provider reviews, not to fill a glossary.