SSL / TLS Certificate Checker
Check any site's HTTPS certificate — issuer, validity dates, hostname match, the full trust chain and which TLS versions it negotiates.
SSL / TLS Certificate Checker
Checked live from our server against public hosts only — private, loopback and internal targets are blocked. Implicit-TLS ports (443, 993, 995, 8443…); STARTTLS is not tested.
Enter a hostname to inspect the SSL/TLS certificate a server presents. The check runs from our end, exactly as a browser would see it, and reports the certificate's subject and issuer, its validity window and days remaining, whether the hostname matches the certificate's SANs, the key type and signature algorithm, and the complete certificate chain from leaf to root.
It also shows the TLS protocol and cipher negotiated and grades the endpoint, flagging common problems: an expired or soon-to-expire certificate, a hostname mismatch, a self-signed or incomplete chain, and weak keys or signatures. It is the fastest way to confirm a new HTTPS deployment, diagnose a browser trust warning, or keep an eye on renewal dates. Checks cover public hosts on implicit-TLS ports (443, 993, 995, 8443 and similar); STARTTLS protocols are not tested.