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.

7 hosts · 230 ms

HostCertsFirst seenLast seen
nsfcu.org 8 2026-05-07 2026-09-02
mailsafe.nsfcu.org 1 2025-12-20 2025-12-20
www.mailsafe.nsfcu.org 1 2025-12-20 2025-12-20
messages.nsfcu.org 2 2025-09-10 2026-08-11
www.nsfcu.org 10 2026-05-07 2026-09-03
nscardwiz.nsfcu.org 3 2025-09-24 2026-09-23
www.nscardwiz.nsfcu.org 3 2025-09-24 2026-09-23

Programmatic access: API GET /v1/hosts/nsfcu.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/nsfcu.org.