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.

6 hosts · 249 ms

HostCertsFirst seenLast seenDNS
syntrusachmea.nl 1 2026-06-08 2026-06-08 ok
e.syntrusachmea.nl 1 2026-01-07 2026-01-07 ok
click.syntrusachmea.nl 1 2026-01-19 2026-01-19 ok
pensioenplanner.syntrusachmea.nl 1 2026-05-19 2026-05-19 ok
acc-pensioenplanner.syntrusachmea.nl 3 2025-08-11 2026-08-18 ok
www.syntrusachmea.nl 1 2026-06-08 2026-06-08 ok

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