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.

9 hosts · 326 ms

HostCertsFirst seenLast seenDNS
dmarcadvisor.com 6 2026-05-29 2026-09-26 ok
*.dmarcadvisor.com 1 2026-06-24 2026-06-24 —
web.dmarcadvisor.com 5 2026-05-30 2026-09-27 ok
m.dmarcadvisor.com 5 2026-05-18 2026-09-16 ok
geo.dmarcadvisor.com 5 2026-05-20 2026-09-17 ok
mta-sts.dmarcadvisor.com 3 2026-05-13 2026-08-29 ok
deployment.dmarcadvisor.com 5 2026-05-29 2026-09-26 ok
eu.dmarcadvisor.com 1 2026-02-11 2026-02-11 ok
www.dmarcadvisor.com 5 2026-05-29 2026-09-26 ok

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