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 · 242 ms

HostCertsFirst seenLast seen
cloud.e.principal.com 2 2025-10-14 2026-10-01
image.e.principal.com 2 2025-10-08 2026-01-07
click.e.principal.com 2 2025-07-30 2026-07-17
pages.e.principal.com 2 2025-07-31 2026-07-18
view.e.principal.com 2 2025-07-31 2026-07-24

Programmatic access: API GET /v1/hosts/e.principal.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/e.principal.com.