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.

3 hosts · 242 ms

HostCertsFirst seenLast seenDNS
staffdefense.com 1 2026-02-10 2026-02-10 ok
autodiscover.staffdefense.com 2 2025-08-11 2026-08-07 ok
www.staffdefense.com 1 2026-02-10 2026-02-10 ok

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