Quick answer: A VPN kill switch blocks normal internet traffic when the VPN tunnel drops, reducing the chance that your real IP or DNS requests leak through the original network.
A VPN can disconnect because of weak Wi-Fi, server issues, device sleep, or network switching. Without a kill switch, apps may continue using the original network after the tunnel drops.
What a kill switch does
A kill switch is a fail-safe. It does not make a VPN anonymous, but it can stop traffic from falling back to the local network during a disconnect.
- It can block browser traffic after a VPN drop.
- It can reduce background app leaks.
- It can help avoid DNS fallback to the local ISP.
- It is useful on public Wi-Fi and long-running sessions.
When to enable it
| Scenario | Recommendation | Reason |
|---|---|---|
| Public Wi-Fi | Enable | Networks can be unstable |
| File transfers | Enable | Background traffic may continue |
| Important accounts | Use carefully | Region changes can trigger checks |
| Casual browsing | Optional | May interrupt reconnect behavior |
How to test it
- Connect the VPN and confirm the public IP changed.
- Open an IP check page in the browser.
- Disconnect the VPN manually.
- Confirm traffic stops instead of falling back to the real IP.
- Reconnect and run DNS and WebRTC checks.
Common questions
Why does the internet stop after enabling a kill switch?
That is expected if the VPN is disconnected. The feature blocks traffic until the VPN reconnects or the setting is disabled.
Does a kill switch stop WebRTC leaks?
Not always. WebRTC is browser-level behavior and should be tested separately.
Do phones need a kill switch?
Phones benefit from similar protections, especially when switching between Wi-Fi and mobile data.
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