If the port closes, you will know.

Not everything speaks HTTP. Port monitors open a TCP connection to any host and port and alert you when the handshake fails.

What you can monitor

Database servers on 5432 or 3306, Redis on 6379, mail servers on 25, 465, 587 and 993, SSH on 22, VPN endpoints, game servers, and any custom service. Add optional TLS to verify a certificate on non-web ports.

  • Any host and port, IPv4 and IPv6
  • Connection time recorded as response time
  • Optional TLS handshake with certificate expiry
  • Free on every plan

Combine with ping

A ping monitor tells you the host is reachable; a port monitor tells you the service on it is listening. Together they show whether an outage is the network or the application.

Frequently asked questions

Do I need to open my firewall?+

Only for the check location. Our checks come from a fixed IP range in Frankfurt that you can allow-list; it is listed in the dashboard.

Can I monitor UDP?+

Not yet. TCP ports and ICMP ping are supported today.

Monitor a port free

Databases, mail and SSH, checked every minute.

Start free – no card ↗