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.

10 hosts · 355 ms

HostCertsFirst seenLast seenDNS
icbf.com 11 2025-10-30 2026-08-14 ok
*.icbf.com 1 2026-06-02 2026-06-02 —
owa.icbf.com 2 2025-10-30 2025-10-30 nxdomain
www.owa.icbf.com 2 2025-10-30 2025-10-30 nxdomain
hybrid.icbf.com 2 2025-10-30 2025-10-30 ok
icbfwexch.icbf.com 1 2025-10-30 2025-10-30 nxdomain
helpdesk.icbf.com 1 2025-10-30 2025-10-30 ok
autodiscover.icbf.com 2 2025-10-30 2025-10-30 ok
mta-sts.icbf.com 4 2026-04-13 2026-09-07 ok
www.icbf.com 10 2025-10-30 2026-08-15 ok

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