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 · 218 ms

HostCertsFirst seenLast seen
cloud.communication06.nyp.org 1 2026-02-19 2026-02-19
image.communication06.nyp.org 3 2025-06-28 2026-07-16
click.communication06.nyp.org 1 2026-02-19 2026-02-19
view.communication06.nyp.org 1 2026-02-19 2026-02-19

Programmatic access: API GET /v1/hosts/communication06.nyp.org (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/communication06.nyp.org.