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.

6 hosts · 232 ms

HostCertsFirst seenLast seen
boo.community 2 2026-03-08 2026-07-24
*.boo.community 2 2026-03-07 2026-07-23
login.boo.community 5 2026-04-13 2026-10-08
img.event.boo.community 2 2026-08-28 2026-08-28
r.event.boo.community 1 2026-08-28 2026-08-28
test.boo.community 4 2026-06-08 2026-10-09

Programmatic access: API GET /v1/hosts/boo.community (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/boo.community.