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.

5 hosts · 250 ms

HostCertsFirst seenLast seen
kdnuggets.com 33 2026-04-21 2026-10-08
*.kdnuggets.com 18 2026-04-21 2026-10-07
6580aa6286340b3292ce8665.kdnuggets.com 11 2026-06-12 2026-10-08
ai-report.kdnuggets.com 8 2026-04-26 2026-08-22
www.kdnuggets.com 3 2026-05-11 2026-09-12

Programmatic access: API GET /v1/hosts/kdnuggets.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/kdnuggets.com.