Certificate log lookup
Subdomains seen in certificate transparency logs.
The check runs on our server. We do not store the domain.
What this checks
Every public TLS certificate gets logged in certificate transparency logs, permanently and publicly, as part of how browsers trust it. This tool searches those logs for certificates naming this domain and lists the subdomains they cover.
What to look for
This finds real subdomains even when they are not linked from anywhere and were never meant to be public — a staging server, an old marketing microsite, an internal tool with a certificate. The list is capped at 100 names; a domain that hits the cap has more than are shown.
A wildcard certificate hides its names
A certificate for *.example.com covers every subdomain at once without naming any of them, so it shows up here as a wildcard rather than adding to the list.