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.

14 hosts · 352 ms

HostCertsFirst seenLast seenDNS
mfkessai.co.jp 21 2026-04-27 2026-09-02 ok
*.mfkessai.co.jp 20 2025-10-22 2026-09-21 —
b.mfkessai.co.jp 1 2026-04-14 2026-04-14 ok
c.mfkessai.co.jp 5 2026-05-14 2026-09-08 ok
pg.mfkessai.co.jp 8 2026-05-07 2026-09-02 ok
tech.mfkessai.co.jp 5 2026-05-10 2026-09-04 ok
lp-kessai.mfkessai.co.jp 8 2026-05-02 2026-08-28 ok
em.mfkessai.co.jp 18 2026-04-28 2026-08-25 ok
form.mfkessai.co.jp 3 2026-05-07 2026-08-23 ok
fukuokabank-ep.mfkessai.co.jp 5 2026-04-22 2026-09-28 ok
developer.mfkessai.co.jp 4 2026-06-06 2026-10-02 ok
support.mfkessai.co.jp 5 2026-05-19 2026-09-16 ok
www.mfkessai.co.jp 8 2026-05-16 2026-09-11 ok
inquiry.mfkessai.co.jp 4 2026-06-02 2026-09-20 ok

Programmatic access, with DNS A records: API GET /v1/hosts/mfkessai.co.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/mfkessai.co.jp.