What Private Mode Actually Does
Worth knowing: WebRTC's IP-gathering process (ICE candidate collection) runs at the browser engine level in under 1 second, well before most privacy extensions have a chance to intervene — which is why incognito mode alone doesn't stop it.
Private browsing — called Incognito in Chrome, Private Browsing in Firefox and Safari — is designed to prevent your browser from saving history, cookies, and form data to your device after you close the window. That's the entire scope of what it does. It's a local privacy feature, aimed at hiding activity from other people who use the same device, not a network-level privacy or security tool.
Why WebRTC Keeps Working in Private Mode
WebRTC is a browser feature that enables real-time communication like video calls, and it works by requesting IP address information directly from your network hardware to establish the fastest possible connection. This request happens at a level that private browsing's history and cookie clearing simply doesn't touch — the browser feature itself remains fully active regardless of which window mode you're using.
Check whether your browser is exposing your real IP through WebRTC right now, in either browsing mode.
Run the WebRTC Leak Test →A Common Misconception
Because private mode is often described as a "privacy" feature, it's easy to assume it covers network-level exposure the way a VPN does. It doesn't. Someone using private mode alongside a VPN can still leak their real IP through WebRTC if the VPN itself doesn't include specific WebRTC leak protection, since neither private mode nor a basic VPN setup necessarily disables the browser feature responsible for the leak.
How to Actually Prevent a WebRTC Leak
- Disable WebRTC directly in your browser's settings, where supported
- Install a browser extension specifically built to block WebRTC IP leaks
- Use a VPN that explicitly advertises WebRTC leak protection, not just IP masking
- Test after each change to confirm the leak is actually closed
What About "Private" or "Secure" DNS Settings?
Similarly, enabling a private or secure DNS option in your browser addresses DNS-level privacy, not WebRTC exposure — the two are separate systems entirely. A person can have private mode, secure DNS, and a VPN all active simultaneously and still leak their real IP through WebRTC if that specific feature isn't separately addressed.
Testing Is the Only Way to Be Sure
Because WebRTC leaks produce no visible warning in the browser interface, the only reliable way to know your status is to run an actual test rather than assuming any combination of privacy settings covers it. This takes under a minute and requires no installation, making it worth doing any time your browser or VPN setup changes.
Not sure whether an extension is enough on its own? See how leak-shield extensions compare to manually disabling WebRTC.
Read: What Is a WebRTC Leak Shield? →For more background, see MDN's WebRTC documentation (developer.mozilla.org).
Frequently Asked Questions
Does private mode stop WebRTC leaks?
No, not by default. Private or incognito mode prevents your browsing history and cookies from being saved locally, but it does not disable WebRTC, which can still expose your real IP address the same way it would in a normal browser window.
What does private mode actually protect against?
Private mode prevents your browser from saving history, cookies, and site data locally after you close the window. It does not hide your IP address, encrypt your traffic, or stop your internet provider from seeing which sites you visit.
How do I actually stop WebRTC leaks?
Stopping a WebRTC leak requires disabling WebRTC in your browser settings, using a browser extension built for this purpose, or using a VPN that specifically includes WebRTC leak protection — private mode alone doesn't do it.