Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

3 hosts · 216 ms

HostCertsFirst seenLast seen
listbuilding.com 23 2026-04-12 2026-10-06
*.listbuilding.com 23 2026-04-12 2026-10-06
track.listbuilding.com 4 2026-05-11 2026-07-28

Programmatic access: API GET /v1/hosts/listbuilding.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/listbuilding.com.