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.

20 hosts · 385 ms

HostCertsFirst seenLast seenDNS
zacco.com 13 2026-03-10 2026-09-16 ok
*.zacco.com 7 2026-01-26 2026-09-16 —
pwd.zacco.com 2 2025-10-22 2026-06-01 ok
www.pwd.zacco.com 2 2025-10-22 2026-06-01 nxdomain
case-staffing.zacco.com 3 2026-03-20 2026-07-30 ok
stage.case-staffing.zacco.com 4 2026-02-26 2026-07-07 ok
domainwatch.zacco.com 4 2026-04-15 2026-08-15 ok
i.zacco.com 4 2026-04-16 2026-06-11 ok
loki.platform.zacco.com 1 2026-03-24 2026-03-24 nxdomain
insight.platform.zacco.com 2 2026-03-20 2026-07-31 ok
login.zacco.com 1 2025-12-30 2025-12-30 ok
certauth.login.zacco.com 1 2025-12-30 2025-12-30 nxdomain
enterpriseregistration.zacco.com 1 2025-12-30 2025-12-30 ok
test-redirector.zacco.com 9 2026-05-28 2026-09-24 ok
awareness.zacco.com 1 2025-10-22 2025-10-22 ok
www.awareness.zacco.com 1 2025-10-22 2025-10-22 nxdomain
testredirect.zacco.com 4 2026-06-09 2026-06-11 ok
ipview.zacco.com 1 2026-07-23 2026-07-23 ok
stage.ipview.zacco.com 5 2026-04-15 2026-08-26 ok
www.zacco.com 8 2026-04-16 2026-08-09 ok

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