WebRTC & DNS Leaks Explained
A VPN hides your IP — but only if nothing leaks. WebRTC and DNS leaks are the two most common ways your real IP or browsing activity can slip out anyway. Here is how they work and how to test for them.
A WebRTC leak exposes your real local IP through your browser's WebRTC feature, even while a VPN is on. A DNS leak sends your DNS requests to your ISP instead of through the VPN tunnel, letting your provider see which sites you visit. Both defeat the purpose of a VPN — and both are easy to test for.
WebRTC leak vs DNS leak at a glance
| Feature | WebRTC leak | DNS leak |
|---|---|---|
| What leaks | Your real local IP | Your DNS queries |
| Who sees it | Websites you visit | Your ISP |
| Cause | Browser WebRTC bypasses VPN | DNS requests bypass VPN tunnel |
| Risk | Reveals true location | Reveals browsing activity |
| How to test | WebRTC Leak Test | DNS Leak Test |
What is a WebRTC leak?
WebRTC is a browser feature that enables real-time communication — video calls, voice, file sharing — directly between browsers. To do this, it needs to discover your local network addresses. In some browsers, this discovery happens even when you are connected to a VPN, and it can reveal your real local IP address to any website that asks.
This is a serious privacy issue: a website can use a WebRTC leak to learn your true location and identity, completely bypassing the VPN. The fix is to disable WebRTC in your browser or use a VPN with built-in WebRTC protection.
What is a DNS leak?
When you type a website address, your device asks a DNS server to translate it into an IP address. With a VPN, these requests should travel through the encrypted tunnel to the VPN's DNS server. A DNS leak happens when the requests instead go to your internet provider's DNS servers.
The result: your ISP can see every website you visit, even though your IP appears hidden. This is usually caused by a misconfigured VPN or an operating system that keeps using the default DNS settings.
Why leaks matter
If you use a VPN for privacy — whether to hide your location, protect your browsing from your ISP, or stay anonymous — a leak undermines the whole point. A WebRTC leak can reveal exactly where you are. A DNS leak can reveal exactly what you do online. Testing for both is quick and free, and it is the only way to know your VPN is actually working.
Test for leaks right now
Run the IPChecks VPN Check — one combined verdict that tests your public IP, WebRTC and DNS for leaks.
Run VPN Check →Frequently asked questions
What is a WebRTC leak?
A WebRTC leak happens when your browser's WebRTC feature reveals your real local IP address even while you are connected to a VPN. This can expose your true location and identity to websites, defeating the purpose of the VPN.
What is a DNS leak?
A DNS leak happens when your DNS requests are sent to your internet provider's servers instead of through your VPN's encrypted tunnel. This lets your ISP see which websites you visit, even though your IP appears hidden.
How do I test for WebRTC and DNS leaks?
Use the IPChecks WebRTC Leak Test to check if your real IP is exposed through WebRTC, and the DNS Leak Test to check whether your DNS requests are leaking to your ISP. The VPN Check combines all three into one verdict.
How do I fix a WebRTC leak?
Disable WebRTC in your browser settings or use a browser extension that blocks it. Some VPNs also offer a built-in WebRTC leak protection. The exact steps depend on your browser.
How do I fix a DNS leak?
Enable your VPN's built-in DNS leak protection, or manually set your DNS servers to a privacy-friendly provider. The goal is to make sure all DNS requests go through the VPN tunnel.