Which port should I use?

TCP ping

Can we open a connection to this port, and how fast?

Tested from around the worldPlain English + technicalFree, no sign-up

The health check runs this and 30 more checks on a domain, then ranks what to fix.

Firewalls, switches and Wi-Fi bundled for homes and offices.

Measure how long a TCP connection to a port takes (like ping, but works through firewalls that block ICMP).

Every result comes in two styles: plain English for everyone, and the exact technical detail for engineers, with the raw JSON one click away.

443 for websites, 22 for SSH, 3389 for Remote Desktop.