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.

8 hosts · 231 ms

HostCertsFirst seenLast seenDNS
caskx.com 11 2026-04-11 2026-10-05 ok
*.caskx.com 6 2026-04-18 2026-10-05 —
secure.caskx.com 1 2026-09-24 2026-09-24 ok
staging.caskx.com 5 2026-05-25 2026-09-22 ok
api.caskx.com 5 2026-05-03 2026-09-01 ok
affiliates.caskx.com 5 2026-05-14 2026-09-12 ok
staging-affiliates.caskx.com 5 2026-05-14 2026-09-13 ok
www.caskx.com 5 2026-04-11 2026-08-09 ok

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