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
ca.sports.comms.yahoo.net 5 2026-02-03 2026-09-28 ok
e.sports.comms.yahoo.net 5 2026-02-03 2026-09-28 ok
images.sports.comms.yahoo.net 4 2026-02-03 2026-09-28 ok
view.sports.comms.yahoo.net 4 2026-02-03 2026-09-28 ok

Programmatic access, with DNS A records: API GET /v1/hosts/sports.comms.yahoo.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/sports.comms.yahoo.net.