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 · 304 ms

HostCertsFirst seenLast seenDNS
jem-net.co.jp 5 2026-05-24 2026-09-21 ok
jemediweb.jem-net.co.jp 2 2025-07-28 2026-08-19 ok
saiyoweb.jem-net.co.jp 4 2026-04-13 2026-08-11 ok
www.jem-net.co.jp 5 2026-05-24 2026-09-21 ok

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