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.

3 hosts · 243 ms

HostCertsFirst seenLast seenDNS
qmainc.com 20 2026-04-15 2026-10-04 ok
*.qmainc.com 18 2026-05-05 2026-10-04 —
www.qmainc.com 2 2026-04-15 2026-06-16 ok

Programmatic access, with DNS A records: API GET /v1/hosts/qmainc.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/qmainc.com.