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.

4 hosts · 244 ms

HostCertsFirst seenLast seenDNS
internet.gmo 1 2025-11-12 2025-11-12 ok
*.internet.gmo 1 2025-11-12 2025-11-12 —
adengineer.internet.gmo 3 2025-08-27 2026-09-25 ok
note.recruit.internet.gmo 4 2026-05-29 2026-09-26 ok

Programmatic access, with DNS A records: API GET /v1/hosts/internet.gmo (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/internet.gmo.