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.

3 hosts · 317 ms

HostCertsFirst seenLast seen
debtco.nl 8 2026-06-12 2026-10-11
*.debtco.nl 4 2026-06-13 2026-10-11
www.debtco.nl 4 2026-06-12 2026-10-11

Programmatic access: API GET /v1/hosts/debtco.nl (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/debtco.nl.