A VPN kill switch is a critical feature that safeguards your privacy by automatically cutting off your internet connection if your VPN drops unexpectedly. Without a kill switch, a disrupted VPN connection could expose your real IP address, DNS queries, and browsing activity to outsiders, advertisers, or your ISP. When enabled, the kill switch continuously monitors the connection to the VPN server. If it detects a disruption, it immediately blocks all internet traffic to prevent data leaks until the secure tunnel is restored.

Kill switches operate at either the application level or the system level. App-specific kill switches block internet access only for selected applications, allowing other apps like video calls or downloads to continue running. System-level kill switches, also known as network kill switches, cut off all internet traffic across the device for maximum protection.

Most premium VPN services include kill switches, though free or budget VPNs may lack this feature. The setting is often found under labels like "network lock," "auto-disconnection protection," or "leak protection" in your VPN app's security or privacy settings. Enabling and configuring a kill switch turns your VPN into a reliable, set-it-and-forget-it privacy tool.