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.

6 hosts · 330 ms

HostCertsFirst seenLast seenDNS
threebestrated.com 22 2026-04-23 2026-08-20 ok
*.threebestrated.com 16 2026-04-23 2026-08-20 —
dashboard.threebestrated.com 4 2026-04-08 2026-08-07 ok
api.threebestrated.com 4 2026-04-19 2026-08-17 ok
mail.threebestrated.com 5 2026-05-25 2026-09-24 ok
www.threebestrated.com 6 2026-06-06 2026-08-06 ok

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