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.

9 hosts · 233 ms

HostCertsFirst seenLast seenDNS
rockyboots.com 12 2026-05-19 2026-09-30 ok
manage.rockyboots.com 2 2026-04-23 2026-04-23 nxdomain
uarjf.rockyboots.com 7 2026-06-01 2026-09-27 ok
i.rockyboots.com 3 2026-07-09 2026-09-07 ok
sgtm.rockyboots.com 3 2026-05-20 2026-09-04 ok
metrics.rockyboots.com 3 2026-05-03 2026-08-20 ok
images.rockyboots.com 1 2026-08-28 2026-08-28 ok
pages.rockyboots.com 8 2026-04-23 2026-06-21 nxdomain
www.rockyboots.com 16 2026-05-19 2026-09-29 ok

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