VPN Kill Switch: What It Does and When You Need It
A VPN kill switch blocks all internet traffic if the VPN connection drops. Without it, your device falls back to direct internet — potentially exposing your real IP for a few seconds. Enable kill switch if you use a VPN for privacy-sensitive work, journalism, or P2P. For most travel and public Wi-Fi use, it is useful but not critical.
What a kill switch does
When the VPN connection drops — due to server issues, network changes or sleep/wake cycles — your OS normally falls back to a direct connection. This briefly exposes your real IP.
A kill switch blocks all traffic the moment the VPN drops. No fallback. You are offline until the VPN reconnects.
When kill switch matters
Torrenting (your real IP must not appear in peer lists). Journalism or activism in countries with surveillance. Any work where IP leak is a meaningful risk.
When kill switch is less critical
For most travel and public Wi-Fi users, a brief IP exposure during VPN reconnection is inconvenient rather than dangerous. Kill switch is still useful here but not essential.
How to enable it
In Hiddify: Settings > TUN Mode > Block connections when VPN is off. In v2rayNG: the equivalent is System proxy mode combined with firewall rules on Android.
iOS has a built-in kill switch in VPN profile settings — enable 'Prevent IPv6' and use the profile's 'On Demand' setting.
Kill switch and reconnection
With kill switch on, if the VPN drops during a video call, the call will cut out until the VPN reconnects (usually within seconds). Accept this trade-off if privacy is the priority.
Continue with the next logical step
The actions below follow the page intent: start with the primary next step, then use setup, support, or the travel checker if needed.
Frequently asked questions
Kill switch behaviour is provided by the client app (Hiddify, v2RayTun, etc.) rather than the VPN service itself. Enable it in the client settings.
Yes. When the VPN drops, all internet access is blocked — not just specific apps. This is by design.
If IP leak is a meaningful risk for you: yes. For general travel and streaming: it is helpful but the interruption during reconnection may be annoying.
iOS does not have an explicit kill switch toggle, but you can configure always-on VPN with on-demand rules that achieve similar behaviour.