Port Checker
Test TCP port connectivity and scan for open ports on remote hosts.
Single TCP Port Check
Enter host and port details to test TCP connectivity
TCP Port Checking Information
Open TCP Ports
An open TCP port indicates that a service is listening and accepting connections on that port. The connection attempt succeeds and typically responds quickly.
Closed/Filtered Ports
A closed TCP port indicates no service is listening, or the port is blocked by a firewall. Connection attempts will either be rejected or time out.
TCP Protocol Only
This tool checks TCP ports only. TCP is connection-oriented and used by most web services, databases, and application protocols. UDP scanning requires different methods.
Security Note
Only scan hosts you own or have permission to test. Unauthorized port scanning may be considered malicious activity by network administrators.