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 · 154 ms

HostCertsFirst seenLast seen
cld.email.health.amazon.com 2 2026-03-29 2026-09-01
cloud.email.health.amazon.com 1 2026-01-25 2026-01-25
image.email.health.amazon.com 2 2026-01-22 2026-02-19
click.email.health.amazon.com 1 2026-01-25 2026-01-25
view.email.health.amazon.com 1 2026-01-25 2026-01-25

Programmatic access: API GET /v1/hosts/email.health.amazon.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/email.health.amazon.com.