🕶️ VPN / Proxy Leak Detector

Using a VPN is supposed to hide your real IP address behind the VPN provider's server address. However, a well-documented privacy issue called WebRTC leaking can expose your actual local or public IP address even while a VPN connection is active, completely bypassing the protection it's meant to provide. This VPN / Proxy Leak Detector tests your current browser for exactly this vulnerability.

WebRTC is a browser feature that enables direct peer-to-peer audio, video, and data connections. To establish these connections, WebRTC needs to discover your actual network addresses, including your real public-facing IP address, through a process called ICE candidate gathering with STUN servers. This address discovery can happen through ordinary JavaScript on any website, and historically many VPN applications only routed regular web traffic through their encrypted tunnel while leaving this separate WebRTC channel exposed.

How this test works

This tool creates a WebRTC peer connection directly in your browser and requests ICE candidates the same way a real-time communication feature would. It then inspects the addresses returned during that process, categorized as either private local addresses (normal and expected) or any public IP address that gets revealed. The entire test runs locally, no video call is actually established and no data is sent anywhere except to a standard public STUN server used purely for address discovery.

Interpreting your results

If the test shows only private addresses, that's completely normal regardless of VPN use. The real concern arises if a public IP address appears that doesn't match your VPN's server address. If you know your VPN's assigned IP and a different public address shows up here, WebRTC is leaking your genuine network identity around your VPN's protection.

How to fix a WebRTC leak

Most modern browsers offer a setting or extension to disable or restrict WebRTC's IP-handling behavior. Firefox has a built-in flag accessible through about:config. Chrome and Chromium-based browsers typically require a dedicated extension. Many VPN providers have also added specific WebRTC leak protection directly into their client software.

A note on what this tool cannot detect

This test specifically checks for WebRTC-based IP leaks. It does not detect DNS leaks, a separate class of issue requiring different detection techniques.

Testing regularly, especially after updates

Browser updates, VPN client updates, and operating system changes can all potentially reintroduce a WebRTC leak that was previously patched, so it's worth re-running this test periodically rather than assuming a one-time check is permanent. This is especially true after switching VPN providers, installing new browser extensions, or updating your browser to a new major version, any of which could change how WebRTC address discovery behaves.

Choosing a VPN provider with leak protection built in

When evaluating VPN providers, look specifically for documented WebRTC leak protection as a stated feature, along with independent third-party audits of their no-logging claims. A provider that proactively addresses this well-known vulnerability class, rather than leaving it entirely to browser-level settings, generally reflects a more security-conscious engineering approach overall.

Bookmark this test and get in the habit of running it any time you set up a new device, switch networks, or install a new browser extension, since any of these changes could subtly affect how WebRTC address discovery behaves on that particular setup.

Frequently Asked Questions