Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

6 hosts · 213 ms

HostCertsFirst seenLast seen
brandkeeper.jp 2 2025-12-02 2026-03-19
knowledge.brandkeeper.jp 2 2025-12-04 2025-12-04
www.knowledge.brandkeeper.jp 2 2025-12-04 2025-12-04
mail.brandkeeper.jp 5 2026-05-16 2026-08-14
webmail.brandkeeper.jp 3 2026-06-15 2026-08-14
www.brandkeeper.jp 2 2025-12-02 2026-03-19

Programmatic access: API GET /v1/hosts/brandkeeper.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/brandkeeper.jp.