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.

4 hosts · 277 ms

HostCertsFirst seenLast seenDNS
cloud.heydude-email.com 2 2025-09-16 2026-09-04 ok
image.heydude-email.com 3 2025-09-03 2026-07-20 ok
click.heydude-email.com 2 2025-09-16 2026-09-03 ok
view.heydude-email.com 2 2025-09-16 2026-09-04 ok

Programmatic access, with DNS A records: API GET /v1/hosts/heydude-email.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/heydude-email.com.