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 · 316 ms

HostCertsFirst seenLast seenDNS
colonbroom.com 15 2026-04-08 2026-09-29 ok
*.colonbroom.com 15 2026-04-08 2026-09-29 —
i.colonbroom.com 5 2026-04-13 2026-09-18 ok
track.colonbroom.com 1 2026-09-22 2026-09-22 ok
promo.colonbroom.com 5 2026-05-05 2026-09-03 ok
help.colonbroom.com 7 2026-04-08 2026-08-28 ok
shop.colonbroom.com 17 2026-04-12 2026-09-25 ok
feedbacks.colonbroom.com 6 2026-05-20 2026-09-15 ok
get.colonbroom.com 1 2026-03-20 2026-03-20 nxdomain

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