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.

4 hosts · 291 ms

HostCertsFirst seenLast seenDNS
univezorg.nl 7 2026-04-21 2026-09-18 ok
*.univezorg.nl 7 2026-04-21 2026-09-18 —
e.univezorg.nl 3 2026-05-28 2026-08-12 ok
mta-sts.univezorg.nl 2 2026-02-24 2026-07-14 ok

Programmatic access, with DNS A records: API GET /v1/hosts/univezorg.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/univezorg.nl.