Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

2 hosts · 211 ms

HostCertsFirst seenLast seen
d365-marketing-weekly.com 11 2026-05-11 2026-08-30
www.d365-marketing-weekly.com 12 2026-05-13 2026-07-11

Programmatic access: API GET /v1/hosts/d365-marketing-weekly.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/d365-marketing-weekly.com.