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.

5 hosts · 245 ms

HostCertsFirst seenLast seenDNS
kirkhamirontech.com 6 2026-05-04 2026-09-01 ok
marketing.kirkhamirontech.com 5 2026-05-12 2026-09-09 ok
mta-sts.kirkhamirontech.com 4 2026-05-12 2026-07-13 nxdomain
support.kirkhamirontech.com 3 2026-02-13 2026-09-27 ok
www.kirkhamirontech.com 6 2026-05-04 2026-09-01 ok

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