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.

11 hosts · 303 ms

HostCertsFirst seenLast seenDNS
dsty.ac.jp 57 2026-04-10 2026-10-02 ok
*.dsty.ac.jp 22 2026-05-14 2026-10-02 —
fg1.dsty.ac.jp 1 2026-08-06 2026-08-06 ok
koha.dsty.ac.jp 4 2026-04-20 2026-08-18 ok
mta-sts.vorstand.dsty.ac.jp 10 2026-05-14 2026-09-09 ok
fg.dsty.ac.jp 1 2026-08-08 2026-08-08 ok
bibi.dsty.ac.jp 4 2026-04-20 2026-08-18 ok
untis.dsty.ac.jp 5 2026-06-02 2026-09-28 ok
mta-sts.dsty.ac.jp 12 2026-05-14 2026-09-09 ok
mta-sts.sus.dsty.ac.jp 10 2026-05-14 2026-09-09 ok
www.dsty.ac.jp 4 2026-04-10 2026-08-12 ok

Programmatic access, with DNS A records: API GET /v1/hosts/dsty.ac.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/dsty.ac.jp.