What is a VPN kill switch, and who needs it today

Ruheni Mathenge Last updated: September 11, 2022 Read time: 16 minutes Disclosure

A kill switch is a VPN feature not deemed essential but very helpful nevertheless. This article explains what it is, how it works, why you should use it, and who offers it.

Sneak peek at the VPN kill switch

Many top-notch VPN services available today have employed unique features to provide their customers with robust security and privacy. One of those is “Kill Switch,” which lets the users stay secure even when the VPN connection drops. This feature works by blocking your internet access. Kill Switch efficiently detects when you are not connected with a VPN server and makes you offline. Hence, no online traffic will generate until your connection is fully restored. That way, not a single byte of your internet traffic will go unencrypted or without a masked IP. Learn more about the VPN Kill Switch feature in this guide.

Suppose you’re a VPN user on any device of your choice (phone, tablet, or computer). What happens if, for whatever reason, your VPN disconnects without you knowing? If your VPN provider has a kill switch feature, then your device would go offline automatically.

That action would ensure that no information leaves your device on the open Internet without protecting your VPN’s secure tunnel. Furthermore, once you’re offline like this, your IP address won’t be exposed to the world because you’re cut off from the Internet until you restore a secure link to your VPN server. Thus a kill switch will keep your online session’s anonymity and security intact.

Those VPN vendors who include a kill switch have it activated by default most often. However, you can disable it if you so wish. If you do, then you will remain online even as your VPN connection goes offline.

This means that you won’t notice any disruption in your VPN service, but it also means that you will be sending and receiving unencrypted traffic from your device and that your actual IP address will be out there for the rest of the world to find. The whole point in a kill switch is that you cannot receive or send any data at all unless you are within the secure VPN tunnel.

How the kill switch actually works

A VPN kill switch is an exceedingly vigilant piece of software. It keeps monitoring your internet connection, detecting irregularities, blocking your access to the world wide web if you’re not linked to a VPN server, restoring it once things are back on track.

So, as you can see, the kill switch is always performing several tasks simultaneously; let’s have a closer look at each:

  • Monitoring. The VPN kill switch is always keeping a digital eye on your internet connection to your VPN server. It keeps looking for changes in IP address or status.
  • Detection. Monitoring will reveal any change that could render your connection unsafe; then, the kill switch detects that change.
  • Blocking. This is the real trick. Different providers have different blocking policies. Some will stop a set of specific apps only, and some will block everything in your device from reaching the Internet.
  • Restoration. Of course, the issue will be solved-either automatically, or you will do it by hand. So her the monitoring and detection work again to figure out that everything is ok again, and then the kill switch restores your internet access.

So when does the activation happen?

The VPN kill switch comes to life when it detects you’re not within the VPN network anymore. There are a variety of circumstances in which this can happen:

  • Your Internet goes off. If you’re not online with your ISP’s carrier signal, then you can’t possibly be connected to a VPN server, and so the kill switch activates itself.
  • You choose to switch VPN servers. If you need to use a different server in the VPN network ( so you can unlock additional material on a website or improve your connection’s quality), you will have to be off the VPN grid for a few seconds. The kill switch will detect this and kick in.
  • Unreliable connections. Public WiFi hotspots are the main offenders in this regard.
  • Automatic updates. It is possible for your operating system to perform a full update overnight. Then, once all the new software is installed, up and running, it connects back to the Internet but without the VPN active.
  • New firewalls. If you don’t add a rule to your new firewall so that your VPN is accessible, at all times, the firewall will keep it blocked, thus triggering the kill switch.
  • Rebooting or restarting a device. If you forget to connect to your VPN after a restart, your kill switch will keep you offline.

Flavors of VPN kill switches

VPN kill switches come in two varieties: application level and system level.

System-level

The system-level kill switch will disconnect your whole device from the Internet when the VPN connection is severed. Every app or software on your computer, phone, or tablet will thus go offline.

In other words, a system-level kill switch renders your device utterly useless except for the tasks you can perform using your locally available resources only. Your whole device will remain offline until you’re back within the VPN network.

It’s a radical approach, but it has its benefits. This kind of kill switch is very effective in preventing your IP address from leaking.


Application-level

If you’re experienced in digital security issues, you already know that sometimes the best security practices come at the cost of functionality and vice versa. VPN kill switches are no different in that regard. For example, the application-level VPN kill switch can never be as safe as the system-level option.