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.

6 hosts · 264 ms

HostCertsFirst seenLast seenDNS
hdsupply-email.com 12 2026-06-23 2026-08-23 ok
*.hdsupply-email.com 12 2026-06-23 2026-08-23 —
cloud.hdsupply-email.com 2 2025-09-14 2026-09-02 ok
image.hdsupply-email.com 3 2025-09-24 2026-08-31 ok
click.hdsupply-email.com 2 2025-09-14 2026-09-02 ok
view.hdsupply-email.com 2 2025-09-14 2026-09-01 ok

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