What Is a WebRTC Leak and How to Check If Your Browser Is Exposing Your Real IP
You've got a VPN running. You double-checked the connection. Everything looks fine. But somewhere in the background, your browser might be quietly broadcasting your real IP address to every website you visit — without your VPN doing anything to stop it.
This is called a WebRTC leak, and it's one of the most overlooked privacy vulnerabilities for people who rely on VPNs or proxies to stay anonymous online. It doesn't require a hacker, a malware infection, or any kind of technical attack. It's just how browsers work by default — and most people have no idea it's happening.
What Is WebRTC and Why Does It Exist?
WebRTC stands for Web Real-Time Communication. It's a technology built directly into modern browsers that allows things like video calls, voice chats, and peer-to-peer file sharing to work without any plugins or extra software. When you use Google Meet, browser-based video calls, or online gaming platforms, WebRTC is likely what's powering the connection.
To establish these direct connections between users, WebRTC needs to know your actual IP address — not the one your VPN presents to the world, but your real one. It uses a process called STUN (Session Traversal Utilities for NAT) to discover and share this information. Under normal circumstances, that's perfectly fine. The problem is that websites can trigger this process silently, using a few lines of JavaScript, and read your real IP address even while your VPN is active.
Browsers that support WebRTC by default include Chrome, Firefox, Edge, Opera, and most Chromium-based browsers. Safari has more limited WebRTC support, which is why it's less commonly affected.
Why Your VPN Doesn't Always Protect You Here
This is the part that surprises most people. VPNs are excellent at masking your IP address at the network level — they route your traffic through their servers and present their IP to the outside world. But WebRTC operates at the browser level, bypassing the normal network stack in certain situations.
When a site requests your IP through WebRTC, the browser may respond with your real IP address, your local network IP, or both — regardless of whether a VPN is connected. Some VPN providers have built protections into their apps or browser extensions to handle this. Many haven't, or their protection is inconsistent across different browsers.
The result is that someone who believes they're fully anonymous could be leaking their home IP address with every browser session.
How to Check If You Have a WebRTC Leak
The most straightforward way is to use a dedicated WebRTC leak checker. The process is simple:
Disconnect your VPN and visit an IP lookup page to note your real IP address.
Reconnect your VPN and run a WebRTC leak test.
If the test reveals an IP address that matches your real one from step one, you have a leak.
A good WebRTC leak testing tool will show you all IP addresses your browser is exposing through WebRTC, including both public and local network addresses. It checks in real time, so the result reflects exactly what your current browser session is broadcasting — no guesswork involved.
Who Should Actually Be Running These Tests?
The honest answer is anyone who uses a VPN for privacy reasons should run this check at least once. But a few groups have more at stake than others.
Journalists and researchers working with sensitive sources need airtight anonymity. A WebRTC leak can expose a physical location even when every other privacy measure is in place.
Remote workers accessing company networks through VPNs may inadvertently expose internal IP address ranges through WebRTC, giving away information about network structure.
People in countries with restricted internet access rely on VPNs to safely reach blocked content. A leak in that context isn't just a privacy inconvenience — it can carry real consequences.
Privacy-conscious everyday users who simply don't want their browsing habits tied back to their home IP have a reasonable expectation that their VPN is doing its job. A quick test confirms whether that's actually the case.
What to Do If You Find a Leak
If your test shows a WebRTC leak, you have a few options depending on your browser and how much control you want.
In Firefox, you can disable WebRTC entirely through the browser's configuration settings. Type about:config in the address bar, search for media.peerconnection.enabled, and set it to false. This eliminates the leak completely but also disables browser-based video and voice calling features.
In Chrome and Chromium-based browsers, you can't disable WebRTC natively, but you can install a browser extension designed to prevent WebRTC IP leaks. Extensions like WebRTC Network Limiter or uBlock Origin with the right settings handle this reasonably well.
Check your VPN provider's browser extension — if they offer one with WebRTC leak protection built in, that's usually the most seamless solution. It works alongside the VPN rather than requiring separate browser-level changes.
Consider switching VPN providers if your current one doesn't address this at the application level. Relying on browser extensions as a workaround is less reliable than having it handled natively by the VPN itself.
How Often Should You Run a WebRTC Leak Test?
Run one whenever you set up a new VPN. Run one after any browser update, since updates can occasionally reset privacy settings or change how WebRTC behaves. If you switch browsers or install new extensions, test again.
For anyone doing sensitive work, building this into a quick pre-session checklist makes sense. It takes under a minute and removes a significant source of uncertainty about whether your privacy setup is actually holding up.
Conclusion
WebRTC leaks are one of those problems that are invisible until someone points them out — and by the time you find out through a third party rather than your own testing, the damage is already done. Running a WebRTC leak checker is a fast, free way to verify that your browser isn't quietly undermining the privacy tools you've put in place. Make it a habit, not an afterthought.
Frequently Asked Questions
Q: Does a WebRTC leak mean my VPN is completely broken?
A: Not necessarily. Your VPN may be functioning correctly for all other traffic while still allowing WebRTC to expose your IP at the browser level. They're separate layers, and a leak in one doesn't mean the other has failed entirely. That said, it's a significant gap worth fixing.
Q: Can I have a WebRTC leak on mobile?
A: Mobile browsers have varying levels of WebRTC support. Chrome on Android supports WebRTC and can be affected. Safari on iOS has more limited support and is less commonly affected. If you use a browser-based VPN or privacy tool on mobile, it's worth testing regardless of the device.
Q: Will disabling WebRTC break anything on my browser?
A: It will disable browser-based video and voice calling features — things like Google Meet accessed through the browser, certain gaming platforms, or peer-to-peer file sharing tools. If you don't use those features, disabling WebRTC has no practical downside. If you do, using a leak-prevention extension rather than disabling it entirely is a better approach.
Q: Is this only a problem when I'm using a VPN?
A: WebRTC always has the ability to expose your IP address, VPN or no VPN. Without a VPN, your IP is already visible to every site you visit, so a leak isn't introducing any new exposure. The vulnerability specifically matters when you're trying to mask your real IP and WebRTC undermines that effort.
Q: How is a WebRTC leak different from a DNS leak?
A: A DNS leak exposes your real IP through unencrypted DNS queries being sent outside your VPN tunnel. A WebRTC leak exposes it through your browser's peer-to-peer communication features. Both can reveal your identity while a VPN is active, but they happen through entirely different mechanisms and require different fixes.
Q: Do browser extensions for WebRTC protection actually work?
A: The better-known ones do work reliably for most use cases. The key is choosing one that's actively maintained and from a developer with a clear privacy policy. Avoid obscure extensions with few users and no clear track record — in the privacy space, an untrustworthy extension can cause more problems than it solves.
