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 · 337 ms

HostCertsFirst seenLast seenDNS
hourscollection.com 23 2026-04-18 2026-09-19 ok
*.hourscollection.com 14 2026-04-18 2026-09-19 —
www.hourscollection.com 7 2026-04-20 2026-08-30 ok

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