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Port Checker

Check whether a port on your connection is open.

Common

UtilSlate’s server tries to connect to the ports you choose on the address your request comes from. Nothing is stored.

What you get

  • Only your address
  • Open, closed or silent
  • IPv4 and IPv6

Questions

Why is my port closed when I forwarded it?

Check that the program is running and listening, that the router forwards the port to the right device (its local address may have changed), and that the device’s firewall allows it. Many mobile and some home connections share one public address between customers (carrier-grade NAT), so forwarding can’t work at all there; your provider may offer a public address or IPv6.

What does “no answer” mean?

Nothing replied within four seconds: usually a firewall silently dropping the connection, which is the safe default for ports you don’t use.

Why can’t I check port 25?

Cloudflare, where UtilSlate runs, doesn’t allow connections to port 25 (email), to prevent spam. Most home providers block it too.

Is an open port dangerous?

Only if what’s listening is vulnerable or badly configured. Keep only the ports you need open, keep that software updated, and never expose things like remote desktop without strong passwords or a VPN.

Is it free? Do I need an account?

It is free to use and there is nothing to sign up for. There are no watermarks and no daily limits.

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