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.

7 hosts · 301 ms

HostCertsFirst seenLast seen
baculasystems.com 1 2026-05-31 2026-05-31
*.baculasystems.com 2 2026-05-31 2026-09-08
trial.baculasystems.com 7 2026-04-16 2026-10-04
*.trial.baculasystems.com 7 2026-04-16 2026-10-04
train.baculasystems.com 7 2026-05-18 2026-10-08
*.train.baculasystems.com 7 2026-05-18 2026-10-08
*.docs.baculasystems.com 7 2026-05-12 2026-10-07

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