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.

17 hosts · 273 ms

HostCertsFirst seenLast seenDNS
ucscard.co.jp 7 2025-09-05 2026-09-02 ok
*.ucscard.co.jp 2 2025-09-05 2026-09-02 —
tab.ucscard.co.jp 1 2025-09-02 2025-09-02 nxdomain
test-tab.ucscard.co.jp 1 2025-09-02 2025-09-02 nxdomain
cmsprod.ucscard.co.jp 1 2026-02-20 2026-02-20 ok
staging.ucscard.co.jp 3 2025-09-04 2026-08-10 ok
cmsstg.ucscard.co.jp 1 2026-02-20 2026-02-20 ok
h1.mak.ucscard.co.jp 2 2026-03-02 2026-08-06 ok
cloud.mail.ucscard.co.jp 2 2026-03-05 2026-08-06 ok
image.mail.ucscard.co.jp 4 2026-01-21 2026-09-09 ok
click.mail.ucscard.co.jp 2 2026-03-05 2026-08-07 ok
view.mail.ucscard.co.jp 2 2026-03-05 2026-08-06 ok
cacco.ucscard.co.jp 1 2026-07-06 2026-07-06 ok
poincho.ucscard.co.jp 1 2026-06-01 2026-06-01 ok
cms.ucscard.co.jp 1 2025-10-23 2025-10-23 nxdomain
ccnext.ucscard.co.jp 1 2026-07-07 2026-07-07 ok
www.ucscard.co.jp 5 2026-04-07 2026-07-27 ok

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