DNS, WebRTC, and IPv6 Leaks: What They Are + How to Test/Fix

• 10 min read

A VPN should hide your real public IP address. But privacy can fail if parts of your network stack take a different path than you expect. That’s what people mean by DNS leaks, WebRTC leaks, and IPv6 leaks—signals that can reveal your real network even while a VPN is “connected.”

Test your setup (quick)

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VPN Detection

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DNS Lookup

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Browser Info

What is a DNS leak?

DNS is how your device translates names like example.com into IP addresses. A DNS leak occurs when DNS queries go to your ISP (or another resolver) instead of going through your VPN’s DNS. Even if your web traffic is encrypted, DNS can reveal where you’re browsing.

Typical causes

  • VPN app isn’t enforcing VPN DNS
  • Custom DNS settings override the VPN
  • Split tunneling excludes the browser

Fixes that work

  • Enable “Use VPN DNS” (or similar) in the VPN app
  • Disable “smart DNS” features unless you know why you need them
  • Restart the VPN after changing DNS settings

What is an IPv6 leak?

Many networks provide IPv6 alongside IPv4. An IPv6 leak happens when your VPN tunnels IPv4, but your device still uses IPv6 directly to the internet, exposing your real IPv6 address.

Fixes that work

  • Use a VPN provider that supports IPv6 properly
  • Disable IPv6 temporarily if your VPN provider recommends it
  • Re-check after every change

Background (and why this is common): IPv4 vs IPv6.

What is a WebRTC leak?

WebRTC enables real-time voice/video and peer-to-peer connections in browsers. In some configurations, WebRTC can reveal local or route-related IPs. Modern browsers have improved leak protections, but misconfigurations and extensions can still cause surprises.

Fixes that work

  • Disable WebRTC (or limit it) in browser settings, if available
  • Use a separate browser profile for privacy-sensitive sessions
  • Remove conflicting network/privacy extensions temporarily to test

A safe, repeatable “leak test” process

  1. Disconnect VPN → visit Check My IP → note ISP/location.
  2. Connect VPN → run VPN Detection → confirm VPN IP/ASN.
  3. Run DNS Lookup → confirm DNS resolver changes as expected.
  4. If results are inconsistent, change one variable at a time (protocol, DNS setting, server).

Fix “VPN detected” issues too

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