An SSL/TLS certificate is what turns http into https and proves your site's identity to visitors' browsers. This SSL certificate checker connects to any public hostname and reports the full details of the certificate it presents: the issuer (certificate authority), the validity dates, the subject and any Subject Alternative Names, the signature algorithm and key, and whether the hostname you entered actually matches the certificate. It also walks the certificate chain so you can spot a missing intermediate certificate, which is a frequent cause of 'not secure' warnings in some browsers even when the site works in others. Use it to confirm a newly installed certificate is correct, to debug trust errors, or to audit a third-party service. For a focused view of when a certificate expires and how many days remain, use the dedicated SSL expiry checker instead. This tool performs a live network check and stores nothing.
Inspect TLS certificates for any public hostname — expiry, issuer, chain, cipher, and hostname match.
Certificate details are fetched over TLS from the server. Internal hosts, localhost, and private IP ranges are blocked.
