Free Port Checker Tool Online
Check if a TCP port is open on any host with common port presets
Quick Port Diagnostics
Test port connectivity with common presets
Check any TCP port from 1 to 65535 on any hostname or IP address.
Quick-select buttons for common web ports (80, 443), email ports (25, 587, 993), and other popular service ports.
Get immediate feedback on whether a port is open and accepting connections or closed and unreachable.
About Our Port Checker Tool
Our free port checker tests whether a specific TCP port is open and accepting connections on any server or hostname. It includes preset buttons for common service ports and provides instant results. Use it to verify firewall rules, check server availability, and diagnose connectivity issues.
Frequently Asked Questions
What does an open port mean?
An open port means a service is actively listening for connections on that port number. This is expected for services like web servers (port 80/443) and email servers (port 25/587).
Open ports allow network communication but should be limited to only the ports needed for your services.
Unexpectedly open ports may indicate a security concern and should be investigated.
What does a closed port mean?
A closed port means no service is listening on that port, or a firewall is blocking the connection. This is the normal state for unused ports.
If you expect a service to be running on a port that shows as closed, check the service status and firewall rules.
Some firewalls drop packets silently (stealth mode) rather than sending a rejection, which may cause the check to time out.
What are the most common ports?
Port 80 is HTTP (web), port 443 is HTTPS (secure web), port 22 is SSH, port 25 is SMTP (email sending), port 587 is SMTP submission, and port 993 is IMAP SSL (email reading).
Port 3306 is MySQL, port 5432 is PostgreSQL, port 3389 is Remote Desktop, and port 21 is FTP.
Our preset buttons include the most commonly checked ports for quick access.
Can I check my own server ports?
Yes. Enter your server hostname or public IP address and the port you want to check. The tool tests connectivity from our server to your specified host and port.
This is useful for verifying that firewall rules are correctly configured and services are accessible from the internet.
Note that the check tests external connectivity. A port may be accessible locally but blocked by a firewall for external access.