SSL Certificate Checker
SSL Certificate Checker: Expiry, Issuer and Fingerprints
Check the TLS certificate served by any public domain. See who issued it, when it expires, how many days are left, its SHA-1 and SHA-256 fingerprints and every name it covers. Expired certificates are one of the most common causes of sudden outages, so checking before the deadline saves an incident.
How to use it
- Enter a domain such as example.com.
- Press Check SSL.
- Review the days remaining and the covered names.
Frequently asked questions
How far ahead should I renew a certificate?
Renew at least 30 days before expiry, and automate it where possible. Public certificates now have short lifetimes, so manual renewal does not scale.
Why does the certificate not cover my subdomain?
Certificates list the exact names they cover. A wildcard such as *.example.com covers one level of subdomain only.
Does this check the whole chain?
It reads the leaf certificate presented by the server. Use it together with a full chain test if clients report trust errors.