SSL Certificate Checker
Inspect the TLS certificate presented by a public hostname or IP address, including expiry, issuer, hostname match, and negotiated protocol details.
What this result means
A valid certificate and hostname match are important transport-security signals. They do not independently confirm an application's ownership, safety, or content security.
How this check works
Use a hostname, public IP address, or an optional port such as example.com:8443. The checker first resolves the supplied host and permits connections only to public addresses. It then performs a bounded TLS handshake from the service environment.
The certificate subject, issuer, validity dates, SHA-256 fingerprint, and subject alternative names help identify the certificate that was actually presented. A hostname-match warning means the certificate's names do not cover the host you entered, even if the server still completes a TLS connection.
Results can differ by CDN edge, SNI configuration, network path, or a nonstandard port. This tool does not log in, submit data, inspect page content, or test a private/internal address.