// FREE TOOL · NO LOGIN · NO SIGNUP
SSL Certificate Checker
Enter a domain. We open a live TLS handshake on port 443, read the X.509 certificate, and cross-reference Certificate Transparency logs. Instant, free, shareable.
https://
try:
How the SSL checker works
CertFleet's checker reads the certificate that the server actually presents on port 443 — issuer, validity dates, negotiated TLS version, full chain and Subject Alternative Names — and cross-references Certificate Transparency logs to count how many certificates have been issued for the hostname.
Want to be alerted before a certificate expires? Set up continuous monitoring — free for 5 certificates.