Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

3 hosts · 292 ms

HostCertsFirst seenLast seen
data.socio.realmadrid.net 2 2026-01-15 2026-01-15
cdn.socio.realmadrid.net 2 2025-06-30 2025-12-09
www.realmadrid.net 19 2026-02-13 2026-10-08

Programmatic access: API GET /v1/hosts/realmadrid.net (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/realmadrid.net.