Free VPN Port Checker
Check TCP reachability and UDP observations for a public VPN server you own or have permission to test.
Check target ports
Check TCP connectivity from our application server to a VPN server you own or have permission to test.
How to use this tool
Follow these steps to get observations you can interpret and act on.
Enter an authorized target
Use your VPN server’s public hostname or IP address. Test only systems you own or are allowed to inspect.
Choose protocol and ports
Select a preset or enter up to 12 protocol:port pairs, such as TCP:443 or UDP:51820. Match your server configuration.
Review the connection evidence
Look at the protocol, source and response for each port. Investigate firewall and service settings if a TCP connection fails.
How the VPN port checker works
This port test makes network requests from the application server to your chosen public target. Protocol presets help you enter common OpenVPN or WireGuard ports, while custom entries let you check the ports actually configured on your server.
A successful TCP handshake verifies server-to-target reachability. A UDP datagram is sent but a silent service remains inconclusive; GRE cannot be checked as a port, and this test does not measure your ISP’s outbound restrictions.
Understanding your results
- A successful TCP handshake confirms reachability from this application server at the time of the test. It does not authenticate the VPN service.
- A UDP service may ignore an unsolicited datagram. Silence cannot reliably distinguish an open port from filtering or a closed service.
- GRE is an IP protocol, not a TCP or UDP port. The PPTP preset identifies that limitation rather than claiming a GRE connectivity result.
Privacy & important limitations
- The public target and selected ports are sent to the application server, which makes the test connections.
- This does not check your ISP’s outbound VPN restrictions or local port forwarding. A server-side observation uses a different route from your device.
Measured findings include their source and scope. An unavailable check is never counted as a pass, a threat or a score.
Frequently asked questions
Why is my WireGuard port inconclusive?
WireGuard uses UDP and may not answer traffic that is not a valid authenticated message. An unanswered probe cannot prove that the service is unavailable.
Does an open port mean my VPN is secure?
No. Port reachability does not assess authentication, patching or tunnel encryption. Review the VPN configuration and server security separately.