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HTTPS

Port 443 checker

Check whether HTTPS on port 443 is externally reachable and why TCP openness does not guarantee TLS or application health.

Port 443 is the default encrypted web port. It is one of the most common public checks because so many APIs and sites terminate TLS there.

Common uses

  • Secure websites
  • Public APIs
  • Reverse proxies and CDNs

Important nuance

A TCP open result on 443 only proves the socket answered. It does not prove your certificate, origin routing, or application response is healthy.