Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

5 hosts · 292 ms

HostCertsFirst seenLast seen
crcitnow.com 10 2026-06-02 2026-09-29
clientportal.crcitnow.com 15 2026-06-06 2026-10-03
email.mail.crcitnow.com 4 2026-06-07 2026-10-05
preferences.crcitnow.com 5 2026-04-23 2026-08-25
www.crcitnow.com 9 2026-06-02 2026-09-28

Programmatic access: API GET /v1/hosts/crcitnow.com (API key for paging).

Shown here: hostnames with a certificate that is valid now or expired within the last 90 days. The full history since 2013 — hostnames whose last certificate expired earlier — is a Pro plan method: GET /v1/hosts-history/crcitnow.com.