Standard unencrypted web traffic. Used for redirect to 443 and Let's Encrypt challenge. Standard TCP port, used by the HTTP service.
Port 80 is reserved by IANA for the HTTP service. Standard unencrypted web traffic. Used for redirect to 443 and Let's Encrypt challenge.
To find out if port 80 is open on your host (or a third-party's — for diagnostics), use our port checker. Enter a domain and a port number — results arrive in 1-2 seconds.
An open port is a potential attack vector. General rules:
Ping sends ICMP packets to a host and measures response time. Port scanning checks which TCP ports are open and accepting connections — helping diagnose serviceavailability issues.
Choose packet count (3, 4, 6, 10). Stats: min/avg/max latency and packet loss.
Check 14 key ports: HTTP, HTTPS, SSH, FTP, SMTP, MySQL, PostgreSQL, and more.
Testing from our server — see site availability from outside, not just your local network.
Need constant monitoring? Create a monitor — checks every minute with notifications.
availability diagnosis
TCP port scanning
connection debugging
basic health check
Ping check history, host availability monitoring and downtime alerts.
Sign up freeEvery open port is an attacker's entry point. If the service is not used (or uses a different port), close it to minimise attack surface.
From a local machine: <code>nc -zv hostname 80</code> or <code>telnet hostname 80</code>. The online checker is simpler — from different IPs, one click.