Enter any IP address or hostname and scan for open ports. Our tool probes the most commonly used ports and reports back which ones are actively listening, helping you assess what services are publicly exposed on a server.
Open ports correspond to specific services running on a server — HTTP on 80, HTTPS on 443, SSH on 22, and so on. Knowing which ports are open gives you a fast snapshot of what software is active and reachable from the outside world.
Unexpected open ports can indicate misconfigured services or potential vulnerabilities. Use our port checker as a quick first pass when auditing a server's exposure, then follow up with your security team if anything unusual turns up.
FAQS
What is an open port?
A port is a numbered communication endpoint on a networked device. When a port is "open," it means there is a service actively listening for incoming connections on that port. Open ports are how web servers, email servers, and other networked applications receive traffic.
Which ports are considered high risk if left open?
Ports like Telnet (23), FTP (21), and RDP (3389) are frequently targeted by attackers when left exposed to the internet without proper access controls. Even common ports like SSH (22) should be secured with key-based authentication and restricted access where possible.
How do I check which ports are open on a server?
Enter the server's IP address or domain name into the open port checker above and run a scan. The tool will test a range of standard ports and return a list showing which ones are currently accepting connections.
Can I use this tool to check my own server's ports?
Yes. Checking your own server's open ports is a legitimate and recommended security practice. It gives you an external view of what's visible to the internet, which can differ from what appears open when checking from inside your own network.
What's the difference between open, closed, and filtered ports?
An open port is actively accepting connections. A closed port is reachable but has no service listening on it. A filtered port is blocked by a firewall, meaning no response is returned at all. Each status tells you something different about the server's configuration and security posture.
How do I find the DNS records or WHOIS data for a server I'm checking?
Use the DNS Lookup tool to view all DNS records for the associated domain. For ownership and registrar data, the WHOIS Lookup tool will give you a full breakdown of the domain's registration details alongside the IP information you've already found.