Free VPN Kill Switch Test
Monitor live browser requests and server-observed IP addresses during a VPN interruption you mark. Review failures, address changes and recovery without paid IP APIs or simulated results.
Capture your VPN baseline
Connect the VPN you want to test, then capture the IP this site observes. The tool cannot tell whether your VPN is connected. No requests are made until you use the controls.
What this test can establish
It records this browser’s sampled HTTP path to this server. It cannot force a new TCP/QUIC connection for every fetch, detect brief leaks between probes, inspect your firewall, test all applications or certify DNS, WebRTC and both IP families. A proxy or split-tunnel route may affect only this browser. No pass/fail score is fabricated.
Use your provider’s supported test procedure. For example, Mullvad’s documentation distinguishes tunnel-loss protection from intentional disconnection and its separate lockdown behavior. Check the instructions for your own client and platform.
How to use vpn kill switch test
Connect the VPN you intend to test, keep its protection enabled, and capture the address observed by this site.
Optionally enter a distinct non-VPN reference IP you already know. You do not need to disable protections to collect one for this tool.
Start monitoring. Follow your provider’s supported tunnel-loss test procedure, then mark the interruption and reconnection while keeping this tab visible.
Stop or let the bounded window finish. Review the real observations and limitations; reconnect your VPN before resuming sensitive activity.
Privacy and scope
The test sends small HTTP requests to this website. This necessarily exposes the request IP to the server, including a non-VPN IP if that route is used. Normal hosting logs may retain metadata. The optional reference IP is not sent. No third-party IP lookup, Redis record or stored browser history is used.
The tool does not save inputs in browser storage. Reset or leave the page to clear its in-page state. Downloads and clipboard copies remain wherever you save or paste them.
Frequently asked questions
Does this tool disconnect or control my VPN?
No. A browser cannot control your VPN tunnel or inspect your firewall. You capture a baseline while using the intended VPN, start requests, then mark when you interrupt and restore your tunnel using your own VPN’s supported test procedure. Markers record your report, not an independently detected VPN state.
What is actually measured?
Small, fresh, same-origin HTTP requests report the client IP observed by this website’s server. Each response must echo a unique nonce. The timeline shows response times, observed addresses, network failures and service errors. Requests start one at a time, no sooner than three seconds after the previous request completes, with a 4.5-second timeout. Monitoring ends within the selected 15–60 second window.
Can failed requests prove that my kill switch worked?
No. Loss of internet access, DNS or TLS problems, browser restrictions, timeouts and server issues can all cause failures. Failures during a reported interruption followed by successful recovery are consistent with blocking, but do not certify the kill switch. Requests are sampled, can reuse browser connections, and do not inspect packets or other applications.
Does a changed IP automatically mean a leak?
No. VPN exits can rotate, networks can change and IPv4/IPv6 routes can differ. A response using a known non-VPN reference address during an actual tunnel interruption is stronger evidence of exposure on this browser route. This tool cannot determine whether an arbitrary address belongs to a VPN or your ISP.
Should I simply press Disconnect in my VPN app?
Follow your provider’s supported testing instructions. Some providers distinguish an unexpected tunnel failure from an intentional Disconnect or Quit action, and may permit traffic after the latter unless a separate always-on/lockdown feature is enabled. A manual disconnect may therefore test a different behavior than tunnel-loss protection.
What happens if I leave the tab?
New probes pause when the document becomes hidden, and any in-flight request is aborted without counting it as blocking. The original end deadline remains in effect. Background gaps are reported and prevent a blocking-consistency conclusion. Stop or Reset cancels pending work.
Where does the IP data go?
Only this website’s server is contacted; no paid IP provider or third-party probe is used. The server sees the request IP and normal hosting logs may retain request metadata. Results stay in this page unless you copy or download them. The optional reference IP is compared locally and is not added to requests.