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.

13 hosts · 275 ms

HostCertsFirst seenLast seenDNS
sozo.ac.jp 1 2026-03-09 2026-03-09 nodata
*.sozo.ac.jp 1 2026-03-09 2026-03-09 —
ba.sozo.ac.jp 5 2026-05-10 2026-09-07 ok
lib.sozo.ac.jp 2 2025-11-13 2025-11-20 ok
stg.sozo.ac.jp 5 2026-05-15 2026-09-12 ok
moriagetai.sozo.ac.jp 5 2026-05-06 2026-09-04 ok
sslvpn.sozo.ac.jp 1 2025-10-20 2025-10-20 ok
www.sslvpn.sozo.ac.jp 1 2025-10-20 2025-10-20 nxdomain
campus.sozo.ac.jp 1 2026-06-18 2026-06-18 nodata
*.campus.sozo.ac.jp 1 2026-06-18 2026-06-18 —
adsv.sozo.ac.jp 4 2025-06-19 2026-09-02 nodata
www.adsv.sozo.ac.jp 2 2025-06-19 2026-09-02 nxdomain
www.sozo.ac.jp 1 2026-02-24 2026-02-24 ok

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