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 · 262 ms

HostCertsFirst seenLast seenDNS
30d.jp 1 2026-05-14 2026-05-14 ok
metabase.30d.jp 5 2026-05-11 2026-09-14 ok
staging.30d.jp 7 2025-06-09 2026-09-14 ok
*.staging.30d.jp 2 2025-06-09 2026-05-10 —
intg.30d.jp 4 2026-04-20 2026-08-24 ok
support.30d.jp 8 2026-05-08 2026-08-20 ok

Programmatic access, with DNS A records: API GET /v1/hosts/30d.jp (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/30d.jp.