A VPN that is connected is not necessarily a VPN that is working. The app can show a green icon while some of your traffic takes the ordinary route, and nothing on screen will say so. These four checks take about five minutes between them and cover the failure modes that actually occur, in the order they are worth doing.
One: does the address change at all
With the VPN off, look up what address the internet sees for you on any address-checking page. Connect the VPN, reload, and confirm it has changed to one in the country you selected. This catches the simplest failure, which is an app that reports connected while the tunnel never came up, and it is the check most people already know. If the address has not changed, nothing further is worth testing until it does.
Two: are DNS lookups going through the tunnel
A DNS leak is when your device asks your ordinary internet provider to resolve the names of the sites you visit, even though the traffic itself goes through the VPN. The provider learns every site you visited without seeing the content, which defeats much of the point. Any DNS leak test page will list the servers answering for you; they should belong to the VPN provider, not to your home internet company.
Three: is IPv6 leaking around the tunnel
Many networks now carry both IPv4 and IPv6, and a VPN configured only for the first can let IPv6 traffic bypass it entirely, exposing an address that identifies you. The test pages that check for DNS leaks generally report IPv6 too. If it leaks, the provider's app usually has a setting to block IPv6 outright, which is the standard fix and costs nothing.
Four: does the kill switch actually fire
Connect, start something that holds a connection open, then force-quit the VPN app from the operating system rather than pressing disconnect. Traffic should stop dead. If the page keeps loading, the kill switch is off, scoped to applications you did not list, or absent on that platform. This is the check people skip and the one that matters most, because it is the failure that happens while you are not looking.
Questions people ask about test my vpn
How often should I test?
After installing, after a major app or operating system update, and any time you change network setup. The four checks take a few minutes.
What is a DNS leak?
Your device asking your ordinary internet provider to resolve site names while the traffic itself goes through the VPN. The provider learns which sites you visit.
My address changed but a site still knows my country. Why?
Because the address is one signal among several. Account country, payment method, device language and location services are all read by some services.