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.

6 hosts · 214 ms

HostCertsFirst seenLast seen
subsystem-insights-hub.ccig.co.jp 2 2026-08-13 2026-08-13
subsystem-insights-hub-api.ccig.co.jp 2 2026-08-13 2026-08-13
st1.hp.ccig.co.jp 2 2025-07-25 2026-07-27
www.st1.hp.ccig.co.jp 2 2025-07-25 2026-07-27
ccixp.ccig.co.jp 2 2026-08-18 2026-08-18
www.ccig.co.jp 122 2025-07-28 2026-09-28

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