Always stay secure with our permanent kill switch

Posted on March 2nd, 2023 by in Proton News.


Proton VPN is pleased to introduce a new feature for our Windows and Linux apps: a Permanent Kill Switch that protects your device at all times, preventing you from accidentally connecting to the internet without the privacy and security of a Proton VPN connection. 

In this article, we discuss what Permanent Kill Switch does, how to enable it, and how it differs from our regular kill switch feature.

What is a kill switch?

Our kill switch feature blocks all external network traffic to and from your device until the app automatically re-establishes a connection to the same VPN server. This prevents your real IP address from being accidentally exposed on the internet if your VPN session is disrupted (for example, when you change your WiFi network or encounter technical issues). 

The kill switch only engages when you start a VPN connection, and is disabled when you manually disconnect the VPN or shut down your device. 

What is our permanent kill switch?

The permanent kill switch prevents all outgoing and incoming connections outside the VPN interface. This means that your device will not be able to access the internet unless you connect to one of our VPN servers. This includes if you manually disconnect the VPN and when your device is shutting down and starting up. 

When the permanent kill switch is enabled, you cant access the internet unless you connect to a Proton VPN server. 

How to use the permanent kill switch

A Kill Switch icon is now located in the Quick Settings bar of the Proton VPN Windows and Linux apps. Click on it to show all kill switch options. You can enable the Kill Switch, enable the Permanent Kill Switch, or turn Kill Switch Off (this disables both types of Kill Switch).

Learn more about how to use the permanent kill Switch

How to enable the permanent kill switch

How does the permanent kill Switch work?

On Windows, our kill switch and permanent kill switch features use the Windows Filtering Platform, deploying specific filters to block connections outside the VPN interface.

The kill switch uses dynamic filters to block all incoming and outgoing connections when an existing VPN connection drops. It only allows our app to try to reconnect to the last server used. 

The permanent kill switch uses persistent filters that force all outgoing internet connections to go through the VPN interface. If the VPN is not connected for any reason, no internet connections are possible.

On Linux, we create a dummy network interface and redirect all outgoing traffic there to block connections.

Final thoughts

Our team is always developing new ways to improve security and protect your privacy. The permanent kill switch achieves both these aims while also being very easy to use. 

The permanent kill switch provides an additional way to protect your privacy online by ensuring that you never accidentally access the internet without the protection using a VPN brings.

Thank you for your continued support.


What platforms is the permanent kill switch available for?

The permanent kill switch is currently available on our Windows and Linux apps, and for our Linux CLI. It should also be noted that when you configure a kill switch on Android, it works in a similar way to the permanent kill switch, rather than a regular kill switch.

What does the permanent kill switch do?

When the permanent kill switch is enabled, your internet connection is blocked at all times unless you are connected to a VPN server. This includes if you manually disconnect the VPN and when your device is starting up and shutting down.

Should I use the kill switch or the permanent kill switch?

Which option is right for you will depend on your needs. Both kill switches will protect you against accidental VPN disconnections. The permanent kill switch provides additional protection by ensuring you never accidentally access the internet without the VPN enabled.

However, the regular kill switch might be better suited to your needs if you want to access the internet without a VPN (for example, if you want to access a streaming service in your own country).

– The kill switch only works when you are connected to the VPN
– The permanent kill switch works at all times, even if you manually disconnect the VPN

Starting with ProPrivacy and now Proton, Douglas has worked for many years as a technology writer. During this time, he has established himself as a thought leader specializing in online privacy. He has been quoted by the BBC News, national newspapers such as The Independent, The Telegraph, and The Daily Mail, and by international technology publications such as Ars Technica, CNET, and LinuxInsider. Douglas was invited by the EFF to help host a livestream session in support of net neutrality. At Proton, Douglas continues to explore his passion for privacy and all things VPN.

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