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.

5 hosts · 276 ms

HostCertsFirst seenLast seenDNS
cloud.em.target.com 3 2026-03-23 2026-08-24 ok
image.em.target.com 1 2025-11-19 2025-11-19 ok
click.em.target.com 1 2026-05-16 2026-05-16 ok
pages.em.target.com 3 2025-09-04 2026-08-22 ok
view.em.target.com 1 2026-05-14 2026-05-14 ok

Programmatic access, with DNS A records: API GET /v1/hosts/em.target.com (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/em.target.com.