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 · 217 ms

HostCertsFirst seenLast seenDNS
iportal.imamura.jp 1 2026-05-18 2026-05-18 ok
iroot.imamura.jp 1 2025-11-06 2025-11-06 ok

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