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.

4 hosts · 202 ms

HostCertsFirst seenLast seen
cloud.apts.irvinecompany.email 2 2026-04-07 2026-09-08
image.apts.irvinecompany.email 5 2026-04-02 2026-09-07
click.apts.irvinecompany.email 1 2025-11-12 2025-11-12
view.apts.irvinecompany.email 2 2025-11-14 2025-11-14

Programmatic access: API GET /v1/hosts/apts.irvinecompany.email (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/apts.irvinecompany.email.