🔒 SSL Certificate Checker

We query Certificate Transparency (CT) logs to show all SSL/TLS certificates issued for a domain. This includes the certificate issuer (Let's Encrypt, DigiCert, etc.), validity dates, Subject Alternative Names (SANs), and certificate chain. You can see both current and historical certificates.

Expired or misconfigured SSL certificates cause browser security warnings that damage user trust and hurt SEO rankings. Certificate monitoring helps you: renew before expiration, detect unauthorized certificate issuance, verify CAA records are working, and ensure proper SSL configuration across all subdomains.

Certificate Transparency (CT) is a public logging system where Certificate Authorities must record all issued SSL certificates. This helps detect misissued or fraudulent certificates. Our tool queries CT logs to show you every certificate ever issued for your domain - useful for security audits and detecting unauthorized subdomain certificates.

Our tool searches CT logs which include certificates for subdomains. This is also useful for subdomain discovery - if a certificate was issued for staging.example.com, it will appear in results even if you did not know that subdomain existed. Combine with our subdomain finder for comprehensive asset discovery.

Yes! Use our domain watchlist feature to monitor certificate expiration. You can also use the REST API (GET /v1/certificates) to build custom monitoring. For comprehensive domain monitoring including SSL, DNS, and availability, check our domain health tool which provides an overall security score.