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 · 364 ms

HostCertsFirst seenLast seenDNS
pol.dk 5 2025-10-14 2026-08-15 ok
test101.pol.dk 4 2026-04-21 2026-08-17 ok
www.test101.pol.dk 4 2026-04-21 2026-08-17 nxdomain
test102.pol.dk 4 2026-04-21 2026-08-17 ok
www.test102.pol.dk 4 2026-04-21 2026-08-17 nxdomain
test103.pol.dk 4 2026-04-16 2026-08-12 ok
www.test103.pol.dk 4 2026-04-16 2026-08-12 nxdomain
staging.pol.dk 4 2026-04-21 2026-08-17 ok
www.staging.pol.dk 4 2026-04-21 2026-08-17 ok
www.pol.dk 5 2025-10-14 2026-08-15 ok

Programmatic access, with DNS A records: API GET /v1/hosts/pol.dk (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/pol.dk.