SSL Expiry Checker
Check when an SSL certificate expires — monitor expiry dates to prevent unexpected outages.
About SSL/TLS Certificate Checking
SSL/TLS certificates are digital documents that authenticate a website's identity and enable encrypted HTTPS connections. Every certificate has an expiration date — typically 90 days to 2 years. An expired certificate causes browsers to display scary security warnings, breaking user trust and potentially blocking all access to your website.
Certificate monitoring is a critical operational practice. Certificate expiry is a common cause of unexpected outages — many high-profile companies including LinkedIn, Spotify, and Microsoft Azure have experienced downtime from expired certificates. Automated monitoring with alerts at 30, 14, and 7 days before expiry is a DevOps best practice.
Beyond expiry, SSL checkers verify the certificate chain is complete and trusted, the domain name matches the certificate's Common Name or Subject Alternative Names, the cipher suites and TLS version are current (TLS 1.2+), HSTS is enabled, and certificate transparency logs show no unauthorized issuances.