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.

3 hosts · 141 ms

HostCertsFirst seenLast seen
data.email.virginatlantic.com 2 2026-06-11 2026-06-11
cdn.email.virginatlantic.com 2 2026-04-08 2026-09-08
pages.email.virginatlantic.com 2 2026-06-11 2026-06-11

Programmatic access: API GET /v1/hosts/email.virginatlantic.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.virginatlantic.com.