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
nse.nl 1 2026-02-16 2026-02-16
mail2.nse.nl 3 2026-06-25 2026-09-09
mta-sts.nse.nl 4 2026-04-20 2026-08-17
www.nse.nl 1 2026-02-16 2026-02-16

Programmatic access: API GET /v1/hosts/nse.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/nse.nl.