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.

6 hosts · 212 ms

HostCertsFirst seenLast seenDNS
protiviti.jp 3 2025-10-10 2026-07-21 ok
grc-t.protiviti.jp 2 2025-10-24 2026-07-16 ok
www.grc-t.protiviti.jp 2 2025-10-24 2026-07-16 nxdomain
GRC-u.protiviti.jp 2 2025-11-20 2026-07-16 —
www.GRC-u.protiviti.jp 2 2025-11-20 2026-07-16 —
www.protiviti.jp 3 2025-10-10 2026-07-21 ok

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