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Open Ports Lookup: Check Which of Your Ports Are Open

This free open ports lookup tests 23 common ports on your own IP address and shows which ones answer from the internet. It marks risky open ports, such as remote desktop and databases, so you can close them.

By Debmedia Technologies LLP · Kolkata, India · Updated

What Is an Open Ports Lookup?

An open ports lookup checks which numbered network doors on your connection accept incoming traffic from the internet. Every service on a computer, such as a website, a mail server or a remote desktop, listens on a port number. A port that answers from the outside is called open, and each open port is a possible way in.

Use this open ports lookup to confirm that the services you need are reachable, and that the ones you do not need are closed. It tests 23 common ports on your own address and marks the risky ones.

How to Use This Open Ports Lookup

  1. Leave the box empty, or enter the IP address you are visiting from. You can see it with the public IP checker.
  2. Press Check my open ports. The test takes about three seconds.
  3. Read the summary and the checks, then the table of ports with their status.
  4. Close or protect any port marked as risky.

For safety, the tool only tests your own address. Scanning systems that you do not own can break the law and the rules of internet providers.

What the Statuses Mean

StatusMeaning
OpenA program answered the connection. The service is reachable from the internet.
Open, riskyA service that should usually not face the internet, such as a database or remote desktop, is reachable.
ClosedThe address replied that nothing listens on this port.
Filtered or no replyNothing answered. A firewall probably drops the traffic silently.

The official list of port numbers and their services is kept in the IANA port number registry.

Ports That Deserve Attention

  • 22 (SSH): safe only with key logins and regular updates.
  • 3389 (Remote Desktop): one of the most attacked ports. Put it behind a VPN.
  • 445 (SMB): Windows file sharing. It should never face the internet.
  • 3306, 5432, 1433, 6379, 27017: databases and data stores. Keep them private.
  • 21 and 23 (FTP and Telnet): old, unencrypted services. Replace them.

Open Ports at Home

On a normal home connection, almost every port should show as closed or filtered, because the router blocks unsolicited traffic. If a port is open, a device has probably been forwarded on purpose, or a feature such as UPnP opened it automatically. Check your router’s port forwarding list and turn off UPnP if you do not need it.

Next Steps

After you change a firewall rule, run the open ports lookup again to confirm the result. To test whether your connection is reachable and how fast it answers, use the online ping test, and to see the route your traffic takes, use the traceroute tool. Find out who owns your address with the IP WHOIS lookup.

Frequently Asked Questions

A port is a numbered door on a computer. An open port means a program is listening there and accepts connections, such as port 443 for secure websites.
Scanning other people's systems without permission can be abusive and illegal in many places. To keep the tool safe, it only tests the address you are visiting from.
Closed means the address answered that nothing listens there. Filtered means nothing answered at all, which usually means a firewall silently drops the traffic.
Remote desktop (3389), file sharing (445), Telnet (23), VNC (5900) and databases such as MySQL (3306) and Redis (6379) should not face the open internet. Use a firewall or a VPN instead.

Disclaimer: results come from live requests and can change as records and servers change. We cannot guarantee that every answer matches what every visitor sees.