SSL certificate checker

Every SSL check performs a real TLS handshake and reports what it finds: the expiry and not-before dates, the issuer and serial number, the full list of subject alternative names, whether the certificate chains to a trusted root, and the TLS protocol version and cipher that were negotiated. Chain errors and hostname mismatches are flagged the same way a browser would flag them, so you see the same picture as your visitors.

Many sites sit behind a CDN or multiple edge servers, and it is common for one region's edge certificate to be misconfigured, outdated, or expiring sooner than the others, while a check from your own office looks perfectly healthy. Running the same certificate check from 300+ locations worldwide surfaces exactly this kind of regional inconsistency, showing you which locations see a valid certificate and which do not.

This tool tells you the certificate's status right now. Certificates typically renew automatically, and automation can fail silently - a cron job stops running, a new certificate is issued but never loaded, or one node behind a load balancer gets missed. SSL certificate monitoring re-checks your certificate continuously from 300+ locations and sends an alert 30, 7 and 1 day before it expires, plus an immediate alert if the certificate becomes invalid, expired, or is served with a chain error, so nothing lapses unnoticed.