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.

3 hosts · 242 ms

HostCertsFirst seenLast seen
dudzus.com 19 2026-04-20 2026-08-25
*.dudzus.com 12 2026-04-21 2026-08-25
mail.dudzus.com 13 2026-04-12 2026-06-28

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