VPN Leak Test: Free IP and WebRTC Checker

A VPN leak test checks whether your real address slips out while your VPN is switched on. This free VPN leak tester compares your public IP and the addresses your browser exposes through WebRTC with your VPN and ISP addresses, so you can see whether your VPN is actually masking you. It does not test DNS leaks.

What Is a VPN Leak?

A VPN leak happens when information that should travel through the encrypted VPN tunnel reaches websites or networks in the open, revealing your real IP address or location. The VPN may look connected and still fail to hide you.

Leaks usually fall into three groups:

• IP leak: websites see the public IP address your ISP gave you instead of the VPN server address. This can happen when the VPN drops, when traffic bypasses the tunnel, or when only some apps are routed through it.
• WebRTC leak: WebRTC is the browser feature behind video calls and peer-to-peer connections. To set up a connection, a browser can gather network addresses from your device. In some setups, one of those addresses is your real public IP, even though normal page traffic goes through the VPN.
• DNS leak: your device sends domain name lookups to your ISP's resolver instead of the VPN's resolver. Your IP stays hidden, but your ISP can still see which sites you visit.

This tool covers the first two. The interface states plainly that DNS leaks and overall VPN connection status are not measured, so a clean result here does not prove your DNS is private.

How to Use the VPN Leak Tester

You run the test in two passes: first without the VPN to record a baseline, then with the VPN on to compare. Both extra fields are optional, but filling them in gives much clearer answers.

1. Turn your VPN off and open this page.
2. Click Detect my IP to capture your current public IP. This is your ISP baseline. Paste it into the field labeled "Your real/ISP IP (optional, without VPN)".
3. Connect your VPN and choose the server location you normally use.
4. If you know the address of that VPN server, enter it in "Your Expected VPN IP (optional, for comparison)". Your VPN app or account page may list it.
5. Click Detect my IP again to see the public IP you have with the VPN on.
6. Click Run Leak Test. The result panel lists the public IP and any WebRTC addresses your browser reports, each with a label that tells you how it compares with your baseline and expected VPN address.

Changing either address field clears the previous result, so run the test again after editing a value.

Worked Example: Reading a Real Test

Say your ISP assigns you 203.0.113.45 and you plan to use a VPN server at 185.220.101.1. You turn the VPN off, click Detect my IP, and enter 203.0.113.45 as your real IP. You then connect the VPN and enter 185.220.101.1 as the expected VPN IP.

You click Run Leak Test, and three outcomes are possible:

• Clean result: the public IP and every WebRTC address show "Matches expected VPN address". Your browser reveals only the VPN address, so there is no IP or WebRTC leak in this session.
• Leak: one WebRTC address shows "Matches supplied ISP baseline". Your browser is handing out 203.0.113.45, the address you started with, so a site using WebRTC could see your real IP even though the VPN is on.
• Inconclusive but harmless: a WebRTC entry reads "Private or special-use address", for example a local network address starting with 192.168. That is your device's address inside your home network. It is not your public identity, though it can reveal a little about your network setup.

The ISP baseline comparison is checked first, so a match with your real IP is always flagged as exposed, even if it also looks like another category.

How Do You Read the Results?

Each address in the result is sorted into one of five labels. The table shows what each means and what to do next.

What a good result looks like

A good result shows your public IP and WebRTC addresses matching the VPN server you expect, or private addresses only, with nothing matching your ISP baseline. If you left the optional fields blank, a good result still has a public IP that differs from the one you saw with the VPN off.

What to do with an unverified public address

"Public address, ownership unverified" means the address is public but you did not supply anything to match it against. It could be your VPN provider, or it could be your ISP if you skipped the baseline. Run it through an ASN lookup to see which network owns it, or check city and ISP details with the bulk IP lookup. If the owner is your VPN provider, you are fine. If it is your home ISP, the VPN is not covering that path.

What "possibly mDNS" means

Some browsers replace local addresses with random names ending in .local to protect privacy. The tool cannot treat these as IPs, so it labels them as not an IP address. This is normal and is generally a sign the browser is hiding your local address.

When Should You Run a VPN Leak Test?

Run a leak test whenever you rely on a VPN to hide your location or address and you want proof rather than trust. These situations come up most often:

• After installing or configuring a VPN: confirm the setup works before you use it for anything sensitive.
• After switching servers or protocols: a new configuration can behave differently from the old one.
• After a browser or system update: updates can reset privacy settings, including WebRTC behavior.
• Before geo-restricted testing: SEO professionals checking local search results or ads from another country need to be sure the target location is what the sites actually see.
• On public Wi-Fi: check that the VPN is covering your browser before you log in to accounts.
• When something feels off: if a streaming or banking site shows your home region while the VPN is on, test it.

Best Practices, Common Mistakes and Troubleshooting

Most confusing results come from running the test in the wrong order or with the wrong values. These habits keep the comparison trustworthy.

Record the baseline with the VPN off

If you click Detect my IP while the VPN is already on, you will save the VPN address as your "real" IP, and every result will look like a leak. Disconnect first, capture the baseline, then reconnect.

Use the right VPN address

The expected VPN IP is the exit address websites see, which is not always the server hostname you picked in the app. Some providers use several exit addresses per location. If your public IP differs slightly from what you typed but belongs to the same provider, that is usually not a leak. Verify ownership with an ASN lookup or the domain to IP tool if you have a hostname.

Check the format of what you type

Enter a plain IPv4 address such as 185.220.101.1 or an IPv6 address. Extra text, ports or a URL will not be recognized as an address.

Test the browser you actually use

WebRTC results depend on the browser, its settings and any extensions. A leak in one browser may not appear in another, so test each browser you use with the VPN.

If you see a leak

• Turn on any "block WebRTC leaks" or kill switch option in your VPN app.
• Check your browser settings or privacy extensions for a WebRTC setting.
• Reconnect the VPN, then run the test again to confirm the fix.
• If the ISP address still appears, try another server or protocol, or contact your VPN provider.

If WebRTC shows as unavailable

Some browsers or privacy setups block WebRTC completely. In that case there is nothing for the tool to inspect, which is safe from a WebRTC leak standpoint, but you will only get the public IP comparison.

What This Test Cannot Tell You

The test gives an honest snapshot of two things: your public IP and the WebRTC addresses your browser reports. It does not check whether your DNS requests go through the VPN, and it does not confirm that your VPN is connected or that every app on your device is protected.

For DNS, you can inspect how a domain resolves with the DNS lookup tool, but spotting a DNS leak requires a test built to observe which resolver handles your queries. A result is also a single moment in time. A VPN that drops mid-session can leak after a clean test, so retest after reconnecting or changing networks.

Finally, "Public address, ownership unverified" is an intentional limit. The tool tells you what the address matches, not who owns it, because it does not decide on its own that an unknown address is safe.

Check Your VPN Now

A VPN is only useful if your real IP stays hidden, and a two-step test shows you in about a minute. Capture your baseline with the VPN off, reconnect, enter your expected address and run the test above. For more address and DNS utilities, browse the Network and IP tools collection.