What Is a VPN Kill Switch? The Only Guide You'll Ever Need

Deyan Georgiev
close Deyan Georgiev

Updated · Apr 19, 2023

Deyan Georgiev
Website Manager | Joined October 2021

Deyan has been fascinated by technology his whole life. From the first Tetris game all the way to Fa... | See full bio


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A kill switch is a safety feature designed to turn off a machine in case of an emergency. It’s the last resort option, as it may damage the machinery.

Kill switches don’t just come in physical form. They may be incorporated into apps like software virtual private networks (VPNs).

So, what is a VPN kill switch, how does it differ from its tangible counterpart, and how does it work? Read on to get your biggest questions about it answered.

What Is a VPN Kill Switch?

Also known as Network Lock or Internet Kill Switch, a VPN connection kill switch disconnect your device from the internet when your VPN connection fails.

When available, you may be able to control it and enable it only when you want. Keeping it disabled allows you to connect your device to the internet even when your VPN is out. It’s convenient but risky.

How Does a Kill Switch Work?

The connection kill switch feature blocks your computer, tablet, or phone from sending IP (Internet Protocol) and DNS (Domain Name System) traffic when your VPN is not working.

As a result, it prevents your real IP address and DNS queries from leaking out, helping preserve your anonymity online by forcing you to go offline.

Here’s the trick behind the magic.

  1. A connection kill switch keeps an eye on the IP address of your device to ensure that it is still connected to your VPN service.
  2. It detects any change in the status of your device that may hinder the VPN from masking your internet traffic data properly.
  3. It stops your entire device or certain apps from connecting to the internet via a wireless network or mobile data once it senses that something’s wrong with your VPN connectivity.
  4. A kill switch for iPhone, Android-powered phone or tablet, Windows PC, or Mac automatically connects your device to the internet on its own when it's safe.

As mentioned, VPN kill switches can target the whole device or select apps only.

So, how does a kill switch work on a limited number of programs? It will prompt you to select the apps you want to keep from accessing the internet when your VPN isn’t available. At the same time, it won’t block the internet for the rest of the programs.

If your VPN has a built-in internet disconnect switch, it may be activated by default. But don’t assume that it is, for your VPN may crash or its connection may weaken without warning. So, check the settings first.

Active and Passive Kill Switch Protocols

The main difference between active and passive kill switch VPN protocols is the reaction time.

An active kill switch protocol turns on only after learning that the VPN service is already disconnected and relaying the information to the device.

A passive kill switch protocol, on the other hand, cuts off your device ASAP. It immediately keeps the device from transmitting data online the second it stops receiving signals from the VPN server.

Both kill switch VPN protocols can get the job done, but passive ones are more secure.

Reasons for VPN Connection Fails

Even the best VPNs can disconnect from the hardware they’re concealing. These are the most common reasons:

  • VPN Account Problems - First of all, make sure that you’re logged into your VPN service. If you’re signed out, you probably entered incorrect login details or there was some sort of glitch.

Either way, double-check your username and password. If you’re still having difficulty logging into your account, check its status. Maybe it’s inactive because your free trial has expired or your premium license has lapsed.

  • Outdated VPN Software - If the version of your VPN client is old, it won’t work flawlessly. Sooner or later, an Android, iOS, Windows, macOS, or Linux kill switch will detect that something’s amiss and keep your device from using the internet.

Check for updates to ensure that you have the right iteration of the software. If you can’t upgrade it from the settings, uninstall it and download the latest version.

  • Server Malfunction - If your VPN’s server acts up, it will lead to a poor connection. It can be an isolated issue, so you may be able to reconnect to the service through a different server.
  • Server Overload - The VPN servers with the strongest connection can still fail when there’s too many users hooked up to them. 
  • Change of VPN Server - You can trigger loss of connection when switching between VPN servers. This will trigger the kill switch to stop your internet access.
  • Inability to Establish a Tunnel - Your VPN may struggle to connect the client and the server via a tunnel because of IP packet filters and proxy server issues.

The solution to the first is to disable filtering through your device’s TCP/IP properties page. The workaround for the latter is to try a different VPN protocol.

Consider using L2TP/IPSec if you’re connected through OpenVPN, or vice-versa. If PPTP is part of the selection, consider it if either of the first two fails to fix the issue.

  • Weak Internet Connection - Unreliable network connectivity can negatively impact your VPN service. If you could, try a more stable connection to determine whether the other network is the problem.
  • Device Update - If your device needs an update, this might disrupt your connection. Download the necessary update or reboot your computer, tablet, or phone to restore its normal operation.
  • Usage of Multiple Apps - Running too many apps could affect the performance of your VPN, activating its connection kill switch feature in the process.

Close the unnecessary active apps and find out whether you have some running in the background. 

  • Firewall or Antivirus Restriction - Usually, firewalls and VPNs can hardly coexist. The former may block the latter or can’t handle its heavy traffic consistently. The best solution is to add your VPN app as an exception.

But if your antivirus software sees your VPN as a harmful program, it may interfere.

Figure out how to configure your antivirus in a way that won’t interrupt VPN connectivity to avoid triggering its internet cut-off switch.

VPN Services With Kill Switches You Can Trust

Not all VPNs have that feature.

But worry not.

There are third-party kill switch apps up for grabs! Still though, getting a VPN with one included is way more practical.

Below are the VPN services with kill switches we vouch for.


ExpressVPN calls its kill switch as Network Lock. It’s a standard feature for this VPN’s apps for Windows, macOS, Linux, and routers.

ExpressVPN doesn’t have the same kill switch for Android. But its Network Protection can temporarily block internet traffic, third parties can’t intercept, nor can they use it to identify you.

The difference between ExpressVPN’s Network Protection and Network Lock is that the former offers an option to restore unprotected internet connectivity with one click.


NordVPN’s automatic Kill Switch can implement network lock to the entire system or specific apps.

This provider’s VPN Kill Switch Windows version supports both system-wide and app-level network lock. NordVPN’s apps for iOS, Linux, macOS (IKE version) and Android version 8.0 or onward can only do system-wide network. The app for macOS (OpenVPN version) can target certain desktop programs.

Private Internet Access (PIA)

PIA’s kill switch wastes no time to cut off your electronics’ internet connection the second it detects a problem with the VPN service. This feature is available for desktop and iOS- and Android-powered devices.


Like other VPN kill switches, Ivacy’s internet kill switch patches the moment of vulnerability as the VPN service is reconnecting. Although available in both Ivacy apps for Windows and Android, it’s automatically enabled in the latter only.


Kill switch hasn’t been VeePN’s strongest security feature. But the company has taken user feedback to heart. It has successfully fixed its major problems. The feature is available in VeePN’s desktop and mobile apps.

Wrap Up

A kill switch is an important feature every VPN needs. It’s the only thing that can address a potential traffic data leak when the connection is down. 

If your chosen service doesn’t have one, we strongly suggest getting a third-party kill switch software.

After all, safety first, right?


How do I know if traffic is going through VPN?

Testing. The best way to determine whether your chosen VPN actually works as intended is testing. If you don’t have the time or confidence to do it yourself, read our in-depth reviews of sought-after VPN instead. You’ll find the answers to popular questions, such as:
  • What is a VPN kill switch?
  • How does a kill switch work?
  • Which is the best VPN service?

How can I test if my VPN is working?

You can use testing sites like ipleak.net. Some VPN providers offer their own tools. But it would be wise to use a mechanism not developed by a company you’re trying to bust. To know whether your VPN truly helps you surf the Web incognito, run IP address, DNS address, and WebRTC (Web Real-Time Communication) leak tests before and after you switch it on. If the second test reveals your original IP and DNS addresses, then your VPN isn’t working as intended. Furthermore, VPNs usually support multiple deployment methods. You can download them as apps (desktop and mobile) and browser extensions and manually install them to routers and other devices. Test your VPN on as many platforms as possible to help make sure you won’t experience any active data leakage whatever device you’re using it on.

What does the kill switch do?

What is a VPN kill switch really used for?  It’s a safety feature engineered to automatically disconnect your device from the internet when there are issues with your VPN.

How do you test VPN kill switch?

Enable your VPN’s kill switch and then manually interrupt your internet connectivity by turning it off or changing your connection from Wi-Fi to mobile data. Of course, do this while your VPN is running. A good kill switch should be able to detect the change and bring back your VPN service when your network connection stabilizes. It pays to load several testing sites simultaneously as your VPN reconnects in order to spot brief moments of traffic data leakage.

What is NordVPN Kill Switch?

NordVPN’s native kill switch can block the internet throughout the whole device or for specific programs. This feature is available in all of this VPN provider’s apps, but it’s either system-wide or app-level most of the time. If you need a more detailed explanation about what is a VPN kill switch, take a look at our guide above.


Deyan Georgiev

Deyan Georgiev

Deyan has been fascinated by technology his whole life. From the first Tetris game all the way to Falcon Heavy. Working for TechJury is like a dream come true, combining both his passions – writing and technology. In his free time (which is pretty scarce, thanks to his three kids), Deyan enjoys traveling and exploring new places. Always with a few chargers and a couple of gadgets in the backpack. He makes mean dizzying Island Paradise cocktails too.

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