SSL checker
Connects to a host over TLS and reads back the certificate it presents, live. Runs server-side, not in your browser.
What is SSL checker?
Connecting to a live host and reading back the TLS certificate it presents is the fastest way to check when a certificate expires, who issued it, and whether it covers the right domain names.
How to use it
Enter a hostname (and port, if not 443); the tool connects over TLS and reports the certificate's subject, issuer, validity dates, and all covered domain names (SANs).
Example
example.com -> Issuer: DigiCert, Expires in 45 days, SANs: example.com, www.example.com