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.

4 hosts · 209 ms

HostCertsFirst seenLast seen
fbn.ca 2 2026-05-15 2026-08-24
pat-gp1859-central.certif.fbn.ca 1 2026-02-12 2026-02-12
info.fbn.ca 3 2026-05-08 2026-08-24
www.fbn.ca 2 2026-05-15 2026-08-24

Programmatic access: API GET /v1/hosts/fbn.ca (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/fbn.ca.