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.

2 hosts · 255 ms

HostCertsFirst seenLast seenDNS
testaws.jpn-ks.co.jp 2 2025-07-12 2026-06-12 ok
www.jpn-ks.co.jp 2 2025-08-03 2026-07-04 ok

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