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 · 345 ms

HostCertsFirst seenLast seenDNS
gdbimidemo.net 3 2026-05-24 2026-05-29 ok
*.gdbimidemo.net 1 2026-05-29 2026-05-29 —
mediatemple.gdbimidemo.net 1 2026-05-29 2026-05-29 ok
www.gdbimidemo.net 2 2026-05-24 2026-05-29 ok
pay.gdbimidemo.net 3 2026-05-24 2026-07-25 ok
www.pay.gdbimidemo.net 3 2026-05-24 2026-07-25 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/gdbimidemo.net (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/gdbimidemo.net.