SSL certificate checker
Check the TLS certificate a domain is actually serving: expiry date, issuer, hostname coverage and chain length. Reads the live handshake, not a cached database.
Reads the certificate directly from a live TLS handshake — inspects exactly what client browsers receive.
Monitor this domain
Get an alert 30, 14, 7 and 1 days before this certificate expires. Useful to ensure client and production sites never quietly drop offline.
30d · 14d · 7d · 1d before expiry
What this checks
- Expiry — the authoritative
notAftertimestamp parsed directly from the certificate payload. - Hostname coverage — verifies if the requested domain is covered by the Subject Alternative Name (SAN) list or an active wildcard pattern.
- Issuer — the Certificate Authority (CA) that signed and verified the certificate.
- Chain length — the number of certificates transmitted by the server. A chain length of 1 often indicates a missing intermediate certificate, which can fail on non-browser TLS clients.