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 · 292 ms

HostCertsFirst seenLast seenDNS
desk.ms 3 2026-04-22 2026-09-22 ok
*.desk.ms 1 2026-05-06 2026-05-06 —
ia.desk.ms 3 2026-05-08 2026-08-14 ok
sip.desk.ms 2 2026-04-27 2026-04-27 ok

Programmatic access, with DNS A records: API GET /v1/hosts/desk.ms (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/desk.ms.