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.

9 hosts · 321 ms

HostCertsFirst seenLast seenDNS
sparkasse-aachen.de 5 2026-03-31 2026-09-16 ok
psd2-xs2a.sparkasse-aachen.de 2 2025-08-05 2026-06-23 nxdomain
mia.sparkasse-aachen.de 8 2026-04-15 2026-08-11 ok
module.sparkasse-aachen.de 5 2026-03-31 2026-09-16 ok
mailing.sparkasse-aachen.de 5 2026-05-03 2026-08-31 ok
engagiert.sparkasse-aachen.de 2 2026-05-20 2026-05-20 ok
www.engagiert.sparkasse-aachen.de 3 2026-05-21 2026-08-12 ok
new.sparkasse-aachen.de 4 2026-05-31 2026-07-30 ok
www.sparkasse-aachen.de 5 2026-03-31 2026-09-16 ok

Programmatic access, with DNS A records: API GET /v1/hosts/sparkasse-aachen.de (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/sparkasse-aachen.de.