Port Scanner
TCP connect scan — check which ports are open on any host. Scan common ports or define your own list.
Port preset:
How the port scanner works
This tool performs a TCP connect scan (SYN + ACK handshake) from our server to the target host. A port is reported as "open" when the three-way handshake completes successfully. Filtered ports (dropped by firewall) and closed ports (RST response) are both reported as closed. The scan is limited to 50 ports per request with a 2.5-second timeout per port.
Common ports reference
22SSH — secure shell remote access
80 / 443HTTP / HTTPS — web traffic
25 / 587SMTP — email sending (submission)
3306MySQL database
5432PostgreSQL database
3389RDP — Windows Remote Desktop
445SMB — Windows file sharing
53DNS — name resolution