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.

4 hosts · 232 ms

HostCertsFirst seenLast seenDNS
dcm-developers.jp 4 2026-02-13 2026-08-17 nodata
*.dcm-developers.jp 4 2026-02-13 2026-08-17 —
rt.dcm-developers.jp 1 2026-02-18 2026-02-18 ok
*.rt.dcm-developers.jp 1 2026-02-18 2026-02-18 —

Programmatic access, with DNS A records: API GET /v1/hosts/dcm-developers.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/dcm-developers.jp.