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.

2 hosts · 203 ms

HostCertsFirst seenLast seen
chugin-sec.co.jp 3 2025-09-03 2026-09-17
www.chugin-sec.co.jp 3 2025-09-03 2026-09-17

Programmatic access: API GET /v1/hosts/chugin-sec.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/chugin-sec.co.jp.