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.

7 hosts · 265 ms

HostCertsFirst seenLast seenDNS
the-board.jp 3 2025-08-24 2026-08-09 ok
*.the-board.jp 7 2025-06-23 2026-08-09 —
stg-sc.the-board.jp 2 2026-01-21 2026-09-07 ok
template.the-board.jp 6 2026-04-19 2026-08-15 ok
developers.the-board.jp 8 2026-04-26 2026-08-22 ok
support.the-board.jp 2 2026-03-16 2026-09-09 ok
api-gw.the-board.jp 1 2025-12-23 2025-12-23 ok

Programmatic access, with DNS A records: API GET /v1/hosts/the-board.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/the-board.jp.