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.

6 hosts · 290 ms

HostCertsFirst seenLast seenDNS
gmo-office.com 1 2025-12-15 2025-12-15 ok
*.gmo-office.com 4 2025-06-18 2026-07-13 —
api.gmo-office.com 2 2025-12-15 2025-12-15 ok
stg-api.gmo-office.com 2 2025-12-15 2025-12-15 ok
www.gmo-office.com 1 2025-12-15 2025-12-15 ok
stg-www.gmo-office.com 1 2025-12-15 2025-12-15 ok

Programmatic access, with DNS A records: API GET /v1/hosts/gmo-office.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/gmo-office.com.