Runs entirely in your browser. Useful if you're using a proxy or VPN and want to sanity-check what your browser might still be revealing.
WebRTC can expose IP addresses even behind a proxy or VPN, bypassing it entirely at the browser level.
Whether your browser allows sites to read a canvas-based fingerprint used for tracking.
If WebRTC shows an IP address you don't expect, most browsers let you disable WebRTC or install an extension that blocks WebRTC leaks specifically, without breaking video calls entirely. A VPN or proxy on its own does not guarantee WebRTC is covered.
Also check your public IP address to compare against what WebRTC reveals.