What is WebRTC Leak?
A browser vulnerability where WebRTC (used for video calls and peer-to-peer communication) reveals your real IP address even when using a VPN, because WebRTC can access your network interfaces directly.
Also known as: WebRTC IP Leak
WebRTC is a powerful technology that enables browser-based video calls without plugins. But that power comes with a privacy cost: it can expose your real IP address even when you're using a VPN.
How WebRTC Leaks Work
WebRTC needs to discover your network interfaces to establish peer connections:
- Browser uses STUN servers to discover IPs
- Discovers both local and public IPs
- This bypasses VPN/proxy settings
- JavaScript on any page can access these IPs
- Your real IP is exposed
What Gets Leaked
Public IP
- Your real internet IP
- Even when connected to VPN
- Geographic location revealed
Local IPs
- 192.168.x.x, 10.x.x.x addresses
- Reveals network structure
- Can help identify you
Testing for WebRTC Leaks
Quick Test
- Connect to your VPN
- Visit browserleaks.com/webrtc
- Check if real IP appears
What You Should See
- Only VPN's IP address
- Or no IPs at all
- No local network IPs
Preventing WebRTC Leaks
Browser Settings
Firefox:
about:config → media.peerconnection.enabled → false
Brave:
- Settings → Privacy → "Prevent WebRTC leaks" → enabled
Safari:
- Generally safe (limited WebRTC support)
Browser Extensions
- uBlock Origin (has WebRTC control)
- WebRTC Leak Prevent
- Disable WebRTC
VPN Features
- Many VPNs include WebRTC protection
- Browser extensions from VPN providers
- Check your VPN's settings
Trade-offs
Disabling WebRTC
Breaks:
- Video/voice calls in browser
- Some file transfer features
- Screen sharing
- Some games
Preserves:
- Real IP privacy
- Location privacy
Selective Control
- Enable only for trusted sites
- Use separate browser for calls
- Accept some risk vs functionality
Related Terms
Browser Fingerprinting
A tracking technique that collects information about your browser, device, and settings to create a unique identifier. Unlike cookies, fingerprints are nearly impossible to delete and can track you across websites without your knowledge or consent.
DNS Leak
A security flaw where DNS queries bypass your VPN or proxy and are sent through your normal ISP connection, revealing the websites you visit even when your other traffic is protected.
Virtual Private Network
A technology that creates a secure, encrypted connection over a less secure network, such as the public internet. VPNs mask your IP address, encrypt your internet traffic, and can make it appear as though you're browsing from a different location.
Have more questions?
Use our guided flow to get the right next privacy step for WebRTC Leak.
Open Guided Flow