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.

3 hosts · 295 ms

HostCertsFirst seenLast seenDNS
fund.resona-am.co.jp 2 2025-06-12 2026-06-12 ok
xwww.test.resona-am.co.jp 2 2026-06-18 2026-06-18 ok
www.resona-am.co.jp 17 2025-09-02 2026-08-20 ok

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