VPN
What Is a VPN Kill Switch?
How a kill switch prevents accidental traffic leaks when a VPN connection drops.
A VPN kill switch is a safety feature that blocks network traffic when the encrypted tunnel is unavailable. Its purpose is to prevent an app or browser from quietly returning to the normal internet connection after an unexpected VPN disconnect.
What happens during a drop
VPN tunnels can disconnect when a device sleeps, changes from Wi-Fi to mobile data or briefly loses signal. Without protection, the operating system may immediately use the ordinary connection, exposing the device’s usual public IP address.
Different kinds of kill switch
Some apps block all traffic at the device level. Others let you choose particular applications that must never connect outside the tunnel. Device-wide protection is simpler; app-level rules can be useful when only sensitive tools need strict routing.
How to test it
Enable the feature, connect the VPN and start a harmless continuous download or IP-address check. Disconnect the tunnel manually and confirm that traffic stops until the VPN reconnects. Repeat after sleep and after changing networks.
The bottom line
A kill switch reduces accidental exposure, but it cannot protect traffic that was deliberately excluded with split tunneling. Review both settings together.