Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

12 hosts · 300 ms

HostCertsFirst seenLast seenDNS
zsassociates.com 12 2025-06-18 2026-06-02 ok
*.zsassociates.com 3 2025-06-18 2026-05-27 —
spamzilla1.zsassociates.com 4 2025-10-20 2026-09-20 ok
ftp1.zsassociates.com 1 2025-10-16 2025-10-16 ok
spamzilla2.zsassociates.com 4 2025-10-20 2026-09-20 ok
ftp2.zsassociates.com 1 2025-10-16 2025-10-16 ok
spamzilla3.zsassociates.com 4 2025-10-20 2026-09-20 ok
hybrid.zsassociates.com 4 2025-10-20 2026-09-20 ok
mail.zsassociates.com 4 2025-10-20 2026-09-20 ok
zssap.zsassociates.com 2 2025-06-20 2026-05-21 ok
autodiscover.zsassociates.com 4 2025-10-20 2026-09-20 ok
www.zsassociates.com 10 2025-09-22 2026-06-02 ok

Programmatic access, with DNS A records: API GET /v1/hosts/zsassociates.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/zsassociates.com.