🔌 Online TCP Port Checker

Enter a host and port to check if the TCP port is open. Or scan 20 common ports with one click.

Host or IP address

Port number (1–65535)

ℹ️ How it works

The tool attempts to establish a TCP connection to the specified host and port from your browser. An open port means the service responds to connections. Closed means the port is unreachable or blocked by a firewall. Results may differ from local checks due to network restrictions.

# Check port locally via PowerShell

Test-NetConnection -ComputerName 192.168.1.1 -Port 3389
# TcpTestSucceeded : True/False

(New-Object Net.Sockets.TcpClient).Connect("google.com", 443)
# No error = port open