How to prevent it#
| Browser | Setting |
|---|---|
| Firefox | media.peerconnection.enabled = false in about:config, or the network.proxy policy to force proxied candidates only |
| Chrome / Chromium | WebRTC IP handling policy "disable non-proxied UDP" (extension or enterprise policy); anti-detect browsers expose it as a toggle |
| Headless automation | Launch flags that disable WebRTC, or block STUN servers at the network level |
Testing#
Load a WebRTC leak test page through the proxy: the only address listed must be the exit. Scripts and non-browser clients are not affected; the leak is a browser feature.
How it works at ProxShift#
Because ProxShift is TCP-only and never touches the browser, WebRTC candidates cannot travel through it; the fix is on the browser side, and the guides list the settings per browser.