Port 443: HTTPS
Encrypted web traffic over TLS.
- Port
- 443
- Protocol
- TCP
- Service
- HTTPS
- Exposure
- Normal to expose when the host is meant to offer this service
What is port 443 used for?
Websites, APIs and most modern services.
Is it safe to expose port 443 to the internet?
Fine to expose on a web server. Keep TLS current and certificates renewed.
If port 443 seems closed or unreachable
- Check that the HTTPS service is running and listening on port 443, not only on 127.0.0.1.
- Check the firewall on the host itself (Windows Defender Firewall, iptables, nftables, ufw) for a rule that allows TCP 443.
- If the host is behind a router, confirm the forwarding rule points to the correct internal address and that your internet provider does not use carrier-grade NAT.
- Test from outside your own network. A port can be open locally and blocked at the edge, or the other way round.
Using port 443 safely
Port 443 is normally open on a server that provides this service. Keep the software current, use encryption where available and monitor the service like any other public endpoint.
Check whether port 443 is open on your host
The check connects from our server, so it shows what the internet can reach.
Open the port checker