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 · 207 ms

HostCertsFirst seenLast seenDNS
baremail.jp 4 2026-01-07 2026-09-16 ok
*.baremail.jp 2 2026-01-07 2026-01-07 —
test.baremail.jp 4 2026-09-16 2026-09-16 ok

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