How to test a VPN
Updated 21 September 2026 · How we research
You do not need specialist tools to check whether a VPN is doing its job. These checks take about fifteen minutes, and repeating them after any settings change is the single most useful habit in this area.
Record a baseline first
Before connecting, note your real IP address, your ISP's name, your DNS resolvers and an unloaded speed measurement. Without a baseline you cannot tell whether anything changed.
1. Address and DNS
- Connect to a server in a different country.
- Check your public IP address. It must be the VPN's, not yours.
- Run a DNS leak test. Every resolver listed should belong to the VPN.
- Check for an IPv6 address. Either none should appear, or it should be the VPN's.
- Run a WebRTC check in each browser you use; results differ between them.
2. Kill switch
- Start a continuous ping to a public address so you can see traffic flowing.
- Kill the VPN client process from the task manager rather than disconnecting cleanly.
- The ping must fail immediately. If replies continue, the kill switch is not protecting you.
- Repeat by disabling the network adapter, and again after sleep and wake.
3. Protocol comparison
- Pick one server and keep it fixed.
- Measure with WireGuard, then OpenVPN UDP, then OpenVPN TCP.
- Run each measurement three times and keep the median, because single runs are noisy.
- Repeat at a busy time of day. Congestion changes the ranking more than the protocol does.
4. Reconnection behaviour
- Switch from Wi-Fi to cellular on a phone and watch whether the tunnel survives.
- Change server inside the app and look for a gap in protection during handover.
- Reboot with autostart enabled and check whether anything escapes before the tunnel is up.
Recording results honestly
This is the standard we hold ourselves to. Where we have not run a test, we say so rather than publishing a number.
| Record | Why it matters |
|---|---|
| Date and time | Network conditions change; an undated result is not a result |
| Server location and protocol | Without these the number cannot be reproduced |
| Your baseline | A speed figure without a control tells you nothing |
| Number of runs and the median | Single measurements are dominated by noise |
| What you did not test | The most honest part of any test record |
Why you will not find speed charts on this site
Reproducible throughput testing needs controlled conditions, repeated runs and a documented setup. We have not carried out that programme, so we publish no speed figures, scores or rankings derived from them. The methods above let you measure your own connection, which is more useful than someone else's numbers from a different continent.
Frequently asked questions
How do I know if my VPN is actually working?
Check that your public IP address has changed, that every DNS resolver shown belongs to the VPN, and that no IPv6 address from your ISP is visible.
How do I test a kill switch?
Start a continuous ping, then end the VPN client process from the task manager. The ping should fail immediately. If replies continue, traffic is escaping.
Why do my speed results vary so much?
Server load, time of day, routing and your local network all change between runs. Take at least three measurements and use the median.