What is a kill switch?
Important note: As we have reported, Apple’s macOS and iOS operating systems don’t close all existing connections when you connect to a VPN, specifically certain DNS queries from Apple services. But if you use Proton VPN while connected to public WiFi, your sensitive traffic is still safe. We are aware of this issue, and are working towards a possible fix.
A kill switch is a security feature that protects your IP address in case you unexpectedly lose the connection to a Proton VPN server.
In case the connection is interrupted, a kill switch blocks all external network traffic to and from your device until the connection is automatically re-established to the same VPN server.
This means that even though you can’t use the Internet until Proton VPN reconnects, your IP address and DNS queries(new window) are safe from being exposed.
A kill switch is available to all Proton VPN users on macOS, Windows, Linux, and iOS/iPadOS. Newer versions of Android now have built-in kill switch feature, as explained below.
Please note that our regular kill switch feature can’t protect you if you intentionally disconnect from a VPN server. However, the feature does protect you while switching servers with Proton VPN.
Our Windows and Linux apps now also feature a permanent kill switch. In addition to protecting you from accidental VPN disconnections, this prevents you from accidentally using the internet without the VPN turned on, and it will persist when you shut down and restart your device. You will not be able to connect to the internet if you manually disconnect the VPN without also disabling Permanent Kill Switch.
Learn more about our permanent kill switch feature(new window)
How do I enable the kill switch?
Windows
Open the Proton VPN app and go to → Countries tab → Kill Switch icon. You can choose between Kill Switch On and Permanent Kill Switch.
You can also turn either Kill Switch Off from here.
macOS
Open the Proton VPN app and go to → Countries tab → Kill Switch icon → Kill Switch On.
You can also turn either Kill Switch Off from here.
Linux
Open the Proton VPN app and go to Menu (V) → Settings → Features and toggle the Kill switch button on.
Old Linux CLI (v3)
Open a terminal window. To enable the regular kill switch, run:
protonvpn-cli ks --on
Or to enable the permanent kill switch, run:
protonvpn-cli ks --permanent
You disable either kill switch with the following command:
protonvpn-cli ks --off
Android
If you are an Android user (version 8.0+), follow these steps to enable Block connections without VPN. It should 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.
A kill switch is not possible if your device uses Android 7.x or earlier
1. Open the Proton VPN app and go to the Settings tab → Features → Kill Switch.
2. Tap the Open Android settings button.
3. Tap the gear icon next to Proton VPN.
4. Enable Always-on VPN and then Block connections without VPN.
iOS / iPadOS
Open the Proton VPN app and go to Settings → Security Options → Kill Switch to toggle the feature on or off.
Because of the way iOS works, it is not possible to access devices on your local network when the kill switch is enabled.