Why You Should Use A Kill Switch With Your VPN

As virtual private networks (VPNs) grow more popular — especially among older, educated users — their benefits are becoming more widely known. VPNs add an important layer of encryption to internet connections, helping to keep users' data, IP addresses, and activity private. Today, internet users can find them on anything from browsers to Wi-Fi routers, with many paid and free versions. These are some of our favorites.

Adopting a VPN also means exposure to quite a few terms that the average computer user may not be familiar with. One phrase that may sound confusing is "kill switch." While not all VPNs offer a kill switch, those that have them tend to make it a selling point, so it's common to have questions about whether using is worthwhile.

People using a VPN are generally concerned about their privacy and want to avoid being spied on by their service providers, governments, and other entities. As long as the VPN is up, it provides encryption to help with that. But no VPN is perfect, and sometimes these networks go down. A kill switch is designed to watch for when a VPN's connection is suddenly not working, then jump into action by disconnecting the device from the internet.

How a kill switch works

A kill switch acts as a safeguard if something goes wrong with a VPN service. VPNs can sometimes crash because of bugs, overloaded servers, outages, and other problems. If an internet connection persists after that, it can leak data out to internet service provides (ISPs) and others who may be snooping as though the user didn't have a VPN. 

When a kill switch senses that the VPN tunnel used to encrypt and mask internet data is not working, it immediately disconnects the device in question from the internet. In this scenario, the user loses access to what they were doing, but doesn't have to worry about ever being online without the VPN active. When the VPN comes back up after the issue has resolved, the kill switch allows the internet connection to be restored.

There are two different types of kill switches — active and passive — that differ slightly in how they work. Both are automatic, but as AVG explains, they watch internet connections in different ways. An active switch queries the server and waits to identify a connection problem, then sends that information to your device so it can shut down the connection.

A passive kill switch, on the other hand, doesn't waste as much time. It monitors the signal from the VPN server, and when that signal shuts down for any reason, it immediately cuts the connection rather than querying and waiting for data. That makes it a bit faster.

Why users may need a kill switch

Why would users want to enable a kill switch? That depends on the situation, they're useful in a variety of scenarios. If someone is using a VPN to explore banned platforms under a hostile government, it's very important to avoid any kind of legal liability or even detection. Or, the user may not want their ISP to get even a glimpse of what they may be doing online. In a professional capacity, users may deal with very sensitive information using a business VPN, and policy requires them to keep it as secure as possible. 

Beyond those use cases, people may simply be nervous that VPNs could fail without realizing it happened, thereby leaking their IPs or other sensitive data. That could be a serious security risk when users are on a public Wi-Fi network at places such as the airport or café, where they want to keep their data completely private but don't have control over network security or protocols. 

Note that some VPN whitelists can also disable kill switches for specific apps or sites, so users can retain important access without interruption. On the other hand, some VPNs, such as NordVPN, allow users to configure their kill switches to only cut connections to certain apps when their VPN's connection goes down. 

Finally, users should always check the VPN service to see if there's a kill switch, how it works, and what it's compatible with. Some kill switches (and their related features) may only work on certain platforms or with certain browsers, so choosing the right one is important. Common VPNs with kill switches include TorGuard, ExpressVPN, and many others.