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.

5 hosts · 346 ms

HostCertsFirst seenLast seenDNS
gmo-healthtech.com 1 2025-11-18 2025-11-18 ok
*.gmo-healthtech.com 1 2025-11-18 2025-11-18 —
support-healthtechone.gmo-healthtech.com 4 2026-06-26 2026-08-25 ok
terms.gmo-healthtech.com 4 2026-06-26 2026-08-25 ok
support-aichart.gmo-healthtech.com 4 2026-06-26 2026-08-25 ok

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