Port 8443 — HTTPS alternate

TCP registered

What runs on port 8443

The unprivileged counterpart to 443, used by Tomcat and many appliances.

Security considerations

Same exposure as 443 — treat it identically.

Checking whether something is listening

# Linux / macOS — what is bound to the port
sudo lsof -i :8443
sudo ss -lntp | grep :8443

# Windows
netstat -ano | findstr :8443
Get-NetTCPConnection -LocalPort 8443

# is it reachable from outside?
nc -zv example.com 8443
curl -v telnet://example.com:8443

Freeing the port

# find the process, then stop it
sudo lsof -ti :8443 | xargs kill        # Linux / macOS
netstat -ano | findstr :8443            # note the PID, then:
taskkill /PID <pid> /F                    # Windows

Should this port be open to the internet?

Yes — that is what it is for. Make sure whatever is listening is something you intend to expose, and that TLS is configured properly.

Quick reference

Frequently asked questions

Other common ports

• Port 20 — FTP data
• Port 21 — FTP control
• Port 22 — SSH / SFTP
• Port 23 — Telnet
• Port 25 — SMTP
• Port 53 — DNS
• Port 67 — DHCP server
• Port 68 — DHCP client
• Port 69 — TFTP
• Port 80 — HTTP
• Port 110 — POP3
• Port 123 — NTP
• Port 143 — IMAP
• Port 161 — SNMP
• Port 389 — LDAP
• Port 443 — HTTPS
• Port 445 — SMB
• Port 465 — SMTPS

All port numbers