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 · 212 ms

HostCertsFirst seenLast seen
auteur.com 16 2026-05-27 2026-10-05
www.auteur.com 17 2026-05-27 2026-10-07

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