What open ports mean
A port is a numbered channel a service listens on — 443 for HTTPS, 22 for SSH, and so on. When a port is "open" to the internet, any machine can try to connect to whatever service is behind it. That's fine for a web server; it's a risk for things like remote desktop (3389), file sharing (445), or plaintext protocols like Telnet (23) that were never meant to face the public internet.
This scanner checks a fixed, small set of common ports. It reports a service as exposed only if it accepts a connection — and it flags the genuinely risky ones separately from the ordinary web ports.
Self-only, by design
The scanner can only target your own connection's IP address, taken from your request. It ignores any host or port you might try to supply. This is deliberate: it stops the tool from being turned into a way to scan someone else's machine.
How to close an exposed port
- Check your router's port-forwarding rules and remove any you don't need.
- Enable your firewall and block inbound connections to services that shouldn't face the internet.
- Put remote-access services behind a VPN instead of exposing them directly.
Common questions
Can I scan a different IP or host?
No. The scanner only ever targets your own address. Scanning hosts you don't own can be illegal, and we don't build a tool that enables it.
The scan came back inconclusive — why?
Either your public IP couldn't be determined (you may be behind a proxy that hides it), or the network between us accepts every connection, which would make an open/closed reading meaningless. We report that honestly instead of showing a false result.
Related checks
Ports are one kind of exposure. These cover others: