WebRTC powers voice and video calls in the browser. To connect two people directly it gathers network addresses, and a website can read them with a short script, without asking for permission.
What can leak
- Your public IP address, which may differ from the one a VPN shows
- Local network details, although modern browsers usually hide local addresses behind a random name
- The audio and video codecs your browser supports
How to reduce a leak
- Use a VPN app that also handles WebRTC traffic
- Check your browser's privacy settings for WebRTC options
- Test again after any change to confirm the result
How to check yours
Run the PrintLeaks test and open the Network and permissions tab, then compare the result with the address your VPN reports.