SSL Certificate Check

Inspect the TLS certificate a host presents: issuer, names it covers, expiry and protocol.

About this service

About the SSL check

Connects to a TLS port, reads the certificate it presents and tells you who issued it, which names it covers and how long it stays valid. An expired or mismatched certificate is a common reason a TLS tunnel suddenly stops working.

  • Transport. TLS handshake with the host name as SNI, once verified and once without if verification fails.
  • Apps. Any TLS port works, not just 443: try 2053, 8443 or your WS-TLS port.
  • Good to know. Not trusted means this server could not verify the chain; some clients are stricter or more lenient than others.