Find every subdomain
of a domain.

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

6 hosts · 303 ms

HostCertsFirst seenLast seenDNS
dcruzagency.com 12 2026-04-22 2026-09-23 ok
service.dcruzagency.com 5 2026-05-10 2026-09-11 ok
leads.dcruzagency.com 5 2026-05-10 2026-09-12 ok
es.dcruzagency.com 5 2026-05-05 2026-09-04 ok
assistant.dcruzagency.com 5 2026-05-11 2026-09-12 ok
www.dcruzagency.com 12 2026-04-22 2026-09-23 ok

Programmatic access, with DNS A records: API GET /v1/hosts/dcruzagency.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/dcruzagency.com.