Free Network Tool
Check whether your browser reveals a different IP address over WebRTC than the one websites see. Run it after you set up a proxy, a VPN or an antidetect browser profile.
The test sends one STUN request from your browser to Google's public STUN server (stun.l.google.com) to learn which public address WebRTC would reveal, and asks api.ipify.org for your IPv4 and IPv6 address so both kinds can be compared. The comparison runs in your browser and Fusion Proxy stores nothing from it.
Running the test...
Your browser is gathering WebRTC candidates. This takes a few seconds.
Browsers use WebRTC for calls and peer-to-peer connections. It finds your addresses with STUN requests over UDP, and those often leave directly instead of going through the HTTP or SOCKS5 proxy your browser uses for web pages.
A website can start a WebRTC connection in JavaScript without asking for camera or microphone access, and read the addresses it gathers.
When the WebRTC address differs from the IP your requests come from, a site can tell that you use a proxy, and it may see your real IP address.
Most current browsers replace local network addresses with random .local names (mDNS) unless the page has camera or microphone permission, so private IPs leak less often than they used to.
Your browser calls our diagnostics endpoint over HTTPS, the same one the What Is My IP tool uses.
It opens a data channel to itself and asks a public STUN server which address the request came from.
Public addresses come from the STUN answer; local ones come from your network interfaces or their mDNS names.
If a public WebRTC address differs from the HTTP IP, the test reports a possible leak.
The test compares two things: the IP address websites see when your browser loads a page, and the public addresses WebRTC reports. An IPv4 address has to be exactly the same. An IPv6 address counts as the same network when it shares the first 64 bits, because operating systems change the last part of an IPv6 address on their own.
A VPN changes the route of all traffic from the device, UDP included, so STUN requests leave through the VPN and WebRTC reports the VPN’s address. The common exception is IPv6: a VPN that tunnels only IPv4 lets IPv6 leave directly, and the test then shows an IPv6 address of your own provider.
A proxy set in a browser or an antidetect profile only carries the traffic the browser sends to it, which is web requests over TCP. WebRTC gathers its addresses with STUN over UDP, and unless the browser is told otherwise, it sends those requests straight from your connection. That is why the fix for a proxy setup is a browser setting, not a proxy setting.
Install Google's WebRTC Network Limiter extension, or set the WebRtcIPHandling browser policy to disable_non_proxied_udp, so WebRTC either uses the proxy or does not connect.
Open about:config and set media.peerconnection.enabled to false to turn WebRTC off, or set media.peerconnection.ice.default_address_only to true to limit it to your default route.
Go to Settings, Privacy and security, WebRTC IP handling policy, and choose Disable non-proxied UDP.
Multilogin, GoLogin, AdsPower, Dolphin Anty and similar browsers have a WebRTC setting per profile. Set it to replace the address with the proxy IP, or turn WebRTC off, then run this test inside the profile.
They all run in the browser, no signup needed.
About WebRTC leaks, local addresses and this test.
All questions and answersNo. The proxy still carries your web traffic. WebRTC is a separate browser feature that can reach the internet on its own path. Limit it in the browser and run the test again.
A private address does not identify you on the internet, but it adds to your browser fingerprint. Most browsers hide it behind a random .local name; if yours does not, the settings above also stop it.
Your network may have IPv6 while the proxy or this page uses IPv4. WebRTC reports every address it can reach the STUN server from, so an IPv6 address here can reveal your real network even when the IPv4 address matches.
If WebRTC is disabled or blocked, it has nothing to leak. The result can also be empty when a firewall blocks UDP; in that case WebRTC cannot reach STUN servers either.
No. The comparison runs in your browser and its result is never sent to us. The request for your HTTP IP goes to our tool server, which, like for every request, writes the time, your IP and your browser to its technical log for abuse prevention.
Yes. In Chrome, Edge and Brave, the setting that disables non-proxied UDP lets WebRTC run only through the proxy over TCP, or not connect when the proxy cannot carry it. Antidetect browsers can replace the address WebRTC reports with the proxy IP.
It works in browsers that support WebRTC, which includes current Chrome, Edge, Firefox, Safari and Brave. If WebRTC is turned off, the test reports that it revealed no addresses.
Claim 1 GB Free Trial, cancel anytime.
Start Free TrialA card is required. A paid 10 GB plan starts after 7 days unless you cancel. View trial terms.
