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.

8 hosts · 194 ms

HostCertsFirst seenLast seenDNS
planningcenteronline.com 3 2025-10-20 2026-09-09 ok
*.planningcenteronline.com 7 2025-10-20 2026-09-09 —
check-ins-staging.planningcenteronline.com 3 2025-09-14 2026-08-15 ok
*.staging.planningcenteronline.com 2 2026-04-09 2026-09-09 —
check-ins.planningcenteronline.com 3 2025-09-14 2026-08-15 ok
status.planningcenteronline.com 6 2026-04-26 2026-09-24 ok
support.planningcenteronline.com 5 2026-05-25 2026-09-22 ok
push-gateway.planningcenteronline.com 3 2025-10-15 2026-09-15 ok

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