How to Check If Your IP Address Is Leaking (WebRTC & DNS Leaks)

Turning on a proxy or VPN doesn’t automatically mean every part of your browser respects it. Two of the most common ways your real IP address slips through anyway are WebRTC leaks and DNS leaks — and both happen silently, with no warning from your browser.

What is a WebRTC leak?

WebRTC is a browser technology used for real-time video/audio calls (think video conferencing apps running directly in the browser). To connect two people directly without routing all their video through a server, WebRTC negotiates a direct connection — and that negotiation process can expose your real local and public IP addresses, even while a proxy or VPN is active.

This happens because WebRTC operates at a layer that some proxies and even some VPNs don’t intercept. The site doesn’t need to trick you into anything — it’s built into how WebRTC is designed to work.

What is a DNS leak?

Every time you visit a site, your device looks up its IP address via a DNS query first. If your proxy or VPN doesn’t force all DNS queries through its own encrypted DNS servers, your device may fall back to your ISP’s default DNS — which reveals which sites you’re visiting to your ISP, and can sometimes reveal your real location, even though your actual traffic is routed through the VPN/proxy.

How to check for these leaks

WebRTC: Use our Privacy & Browser Leak Checker — it runs a WebRTC connectivity test directly in your browser and shows any IP addresses it can discover, with no data sent to a server.
Your visible public IP: Compare what our What’s My IP tool shows against the IP address you expect your proxy/VPN to present. If they don’t match your VPN provider’s IP, something’s misconfigured.
DNS: Look for a “DNS leak test” feature built into your VPN client — most reputable VPNs include one. If yours doesn’t, that’s worth treating as a red flag on its own.

Fixing a WebRTC leak

Firefox and Chrome both allow WebRTC IP handling policies to be restricted via browser settings or extensions specifically built to plug WebRTC leaks, without disabling video calls entirely.
Some VPN clients include a WebRTC-blocking option — check your VPN’s settings before installing a separate extension.
As a blunt fallback, disabling WebRTC entirely in browser flags stops the leak but also breaks in-browser video calling.

Fixing a DNS leak

Use a VPN or proxy provider that explicitly routes DNS through its own servers and states this clearly in their documentation.
Manually configure a trusted DNS resolver on your device as a backup, rather than relying on whatever your network hands out by default.

The takeaway

“I’m using a VPN” and “nothing about me is leaking” are not the same claim. Given how invisibly these leaks happen, it’s worth actually testing rather than assuming — our tools above take under a minute and run entirely in your browser.