A VPN kill switch is your last line of defense against data leaks when your connection drops. This guide explains how kill switches work, why they matter for privacy, and which VPN providers offer the most reliable protection.
What a VPN kill switch does
When your VPN connection fails, a kill switch instantly blocks all internet traffic until the secure tunnel is restored. Without it:
- Your real IP address could be exposed during brief disconnections
- Unencrypted data might leak to your ISP or network admin
- Ongoing downloads or streams could reveal your location
According to EFF research, even milliseconds of exposure can compromise anonymity when torrenting or accessing sensitive content.
VPNs with reliable kill switches
| Provider | Kill Switch Type | Platforms | Try |
|---|---|---|---|
| ExpressVPN | Network-level (blocks all traffic) | Windows, Mac, Linux, routers | Get ExpressVPN |
| NordVPN | App-level + emergency firewall | All major devices | Get NordVPN |
| Proton VPN | Persistent (survives reboots) | Desktop & mobile | Get Proton VPN |
How to enable your kill switch
- Find the setting: Usually under “Privacy” or “Security” in your VPN app
- Choose protection level: App-level (safer) or system-wide (strictest)
- Test it: Disconnect from VPN manually to verify traffic stops
- For routers: Use VPN-enabled firmware with built-in kill switches
Note: Some providers like Surfshark enable kill switches by default for new installations.
Kill switch FAQs
Does a kill switch slow my internet?
No – it only activates when your VPN fails. During normal use, there's zero speed impact.
Can I bypass the kill switch in emergencies?
Yes, but you must manually disable it in settings. Most apps won't let you temporarily suspend it.
Do mobile VPNs need kill switches?
Critical on Android/iOS when switching between WiFi and mobile data. NordVPN's mobile kill switch survives network hops.
What if my kill switch fails?
Use a DNS leak test tool periodically. Consider firewall-based solutions like Proton VPN's Always-on VPN for maximum protection.
Don't gamble with connection drops
ExpressVPN's network-level kill switch offers the most foolproof protection we've tested, automatically safeguarding all traffic across devices. Their independently audited apps ensure no leaks during sudden disconnections.
