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.

10 hosts · 231 ms

HostCertsFirst seenLast seen
kitagin.co.jp 3 2026-01-08 2026-01-08
apiauth.kitagin.co.jp 1 2025-11-27 2025-11-27
api.kitagin.co.jp 1 2025-11-27 2025-11-27
apiportal.kitagin.co.jp 1 2025-11-27 2025-11-27
ib-toushin.kitagin.co.jp 2 2025-06-19 2026-05-25
cs-toushin.kitagin.co.jp 2 2025-06-19 2026-05-25
webvoucher.kitagin.co.jp 1 2026-04-10 2026-04-10
apiauthtest.kitagin.co.jp 1 2025-11-27 2025-11-27
apitest.kitagin.co.jp 1 2025-11-27 2025-11-27
www.kitagin.co.jp 5 2025-08-28 2026-08-24

Programmatic access: API GET /v1/hosts/kitagin.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/kitagin.co.jp.