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.

9 hosts · 243 ms

HostCertsFirst seenLast seen
collegebaby.com 21 2026-05-12 2026-10-02
staging.collegebaby.com 6 2026-06-03 2026-10-02
staging-ui.collegebaby.com 6 2026-06-03 2026-10-02
login.collegebaby.com 10 2026-04-16 2026-10-10
admin.collegebaby.com 15 2026-05-02 2026-08-31
sidekiq.collegebaby.com 5 2026-05-16 2026-09-14
development.collegebaby.com 5 2026-04-25 2026-08-23
dev.collegebaby.com 11 2026-05-20 2026-10-02
www.collegebaby.com 21 2026-05-12 2026-10-02

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