What is port 8443 used for?
Alternative HTTPS port, common for admin consoles.
Should port 8443 be open?
Open only if you need it. Expose it only when required, with encryption and strong authentication, ideally limited to known IP addresses. Limit admin interfaces on 8443 to known IPs or a VPN.
See what is listening on port 8443
# Linux
sudo ss -tlnp | grep ':8443 '
# macOS
sudo lsof -nP -i TCP:8443 -sTCP:LISTEN
# Windows (PowerShell)
Get-NetTCPConnection -LocalPort 8443 -State ListenOpen or block port 8443 in a firewall
# Ubuntu / Debian (ufw)
sudo ufw allow 8443/tcp
sudo ufw deny 8443/tcp
# Windows (PowerShell, as administrator)
New-NetFirewallRule -DisplayName "Port 8443" -Direction Inbound -Protocol TCP -LocalPort 8443 -Action AllowOn cloud servers, also open the port in the provider’s security group or network firewall. At home, a service behind a router needs a port-forwarding rule to the device’s local IP.
Test it from outside
A port can be open on the server but blocked upstream. The Port Checker connects from the internet, so it shows what the world sees. From your own machine, use nc -vz example.com 8443 (macOS/Linux) or Test-NetConnection example.com -Port 8443 (Windows).
Port CheckerTest whether a server accepts connections on specific ports — web (80/443), mail (25/587/993), SSH, databases or remote desktop — and see which are open, closed or filtered by a firewall.
Open the tool Frequently asked questions
What is port 8443?
Alternative HTTPS port, common for admin consoles.
Is it safe to open port 8443?
Open only if you need it. Expose it only when required, with encryption and strong authentication, ideally limited to known IP addresses.
How do I check if port 8443 is open?
Enter your domain or public IP in the Port Checker with port 8443. It tries a TCP connection from the internet and reports open, closed or filtered.