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.

5 hosts · 262 ms

HostCertsFirst seenLast seenDNS
hivesystems.com 5 2026-05-26 2026-09-09 ok
cmmc.hivesystems.com 4 2026-04-07 2026-08-05 ok
password.hivesystems.com 15 2026-05-02 2026-06-07 ok
bookameeting.hivesystems.com 12 2026-05-22 2026-09-17 ok
www.hivesystems.com 5 2026-05-21 2026-09-08 ok

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