A VPN kill switch is the feature that stops your VPN from failing quietly. Its job is narrow and important: if the encrypted tunnel drops, it blocks your internet connection instantly, so nothing leaves your device over the unprotected line while you carry on unaware.
How It Works
The kill switch monitors the tunnel continuously. A VPN connection is not permanent: it can drop when you move between networks, when a device wakes from sleep, when a server is taken out for maintenance, or when a flaky connection interrupts it for a few seconds.
The moment the tunnel goes down, the kill switch cuts all internet traffic at the device level rather than letting it fall back to your normal connection. Your real IP address and your traffic never reach the network. When the VPN reconnects, traffic resumes.
Why It Matters
The problem a kill switch solves is that a dropped VPN gives you no warning. Pages keep loading, downloads keep running, and everything looks exactly as it did a moment earlier. The only thing that has changed is that you are now exposed, and nothing on screen tells you.
Two situations make that worse than usual. The first is torrenting, where your client keeps running whether or not the tunnel is up and your address becomes visible to every peer in the swarm the instant it drops. The second is public Wi-Fi, where the network you have fallen back onto is precisely the one you were trying to protect yourself from.
A VPN without a kill switch is not a lesser VPN, it is an unpredictable one. It protects you right up until the moment it silently does not.
System-Wide vs App-Level
A system-wide kill switch blocks all internet traffic from the device when the tunnel drops. It is the stricter option and the one to choose if you are unsure, because nothing gets through by accident.
An app-level kill switch, sometimes called app kill or split kill, closes or blocks only the applications you nominate. That suits a specific setup, such as protecting a torrent client while leaving the rest of the machine online. It is more convenient and less thorough, and it only protects what you remembered to add to the list.
How to Turn It On
It is in your VPN app's settings, usually under a connection or privacy heading, and it is not always on by default. Turn it on before you start relying on the VPN rather than after, because the whole point is to be covered during the failure you did not anticipate.
Pair the kill switch with auto-connect on untrusted networks. Between them, you are covered both when you forget to connect and when the connection fails on its own.
Providers We Recommend
Our overall pick, with a reliable system-wide kill switch alongside an app-level option.
The better value option, with the same feature available and unlimited devices on one subscription.
Frequently Asked Questions
Should the kill switch always be on?
For anything privacy-critical, yes. The cost is that your internet stops when the VPN drops, which is mildly annoying and exactly what you are asking for. If you are using a VPN casually to reach a streaming catalogue, you may prefer it off so a dropped connection does not interrupt playback.
Do all VPNs have a kill switch?
Most reputable paid providers do, on at least their desktop apps. Availability is patchier on mobile and on TV platforms, and many free services omit it entirely. If it matters to you, check for it on the specific platform you intend to use rather than assuming the provider supports it everywhere.
Pricing and specs verified August 2026. Check the provider for current pricing.
