CT log tool
Looks up every publicly-logged certificate ever issued for a domain, via crt.sh's Certificate Transparency search. Useful for spotting certificates you didn't request.
What is CT log tool?
Certificate Transparency logs are a public, append-only record of every certificate ever issued for a domain by any participating CA — checking them is how you spot a certificate you never requested, a sign of a possible compromise.
How to use it
Enter a domain to search public CT logs (via crt.sh) for every certificate ever logged against it, showing issuer and validity dates for each.
Example
Searching a domain might reveal 5 historical certificates from 2 different CAs
over the domain's lifetime.