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.

11 hosts · 276 ms

HostCertsFirst seenLast seenDNS
koombea.com 42 2026-03-30 2026-09-24 ok
*.koombea.com 25 2026-03-26 2026-09-24 —
lunch.koombea.com 5 2026-05-16 2026-09-14 ok
ai.koombea.com 8 2026-04-24 2026-08-20 ok
scim.koombea.com 27 2026-05-02 2026-10-05 ok
on.koombea.com 5 2026-05-29 2026-09-27 ok
myapp.koombea.com 1 2026-01-26 2026-01-26 ok
www.checkins.koombea.com 1 2026-02-04 2026-02-04 nodata
reports.koombea.com 3 2026-04-26 2026-08-16 ok
www.koombea.com 15 2026-04-15 2026-08-21 ok
*.www.koombea.com 3 2026-08-21 2026-08-21 —

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