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.

3 hosts · 282 ms

HostCertsFirst seenLast seenDNS
columbiabankingsystem.com 11 2025-07-24 2026-09-01 ok
autodiscover.columbiabankingsystem.com 2 2025-08-20 2026-07-31 ok
www.columbiabankingsystem.com 6 2026-05-06 2026-09-01 ok

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