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 · 373 ms

HostCertsFirst seenLast seenDNS
nbf.ca 2 2026-05-15 2026-08-24 ok
info.nbf.ca 3 2026-05-08 2026-08-24 ok
www.nbf.ca 2 2026-05-15 2026-08-24 ok

Programmatic access, with DNS A records: API GET /v1/hosts/nbf.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/nbf.ca.