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.

7 hosts · 244 ms

HostCertsFirst seenLast seenDNS
kskwn.de 4 2026-03-27 2026-09-12 ok
psd2-xs2a.kskwn.de 2 2025-08-06 2026-06-25 nxdomain
module.kskwn.de 4 2026-03-27 2026-09-12 ok
transfer.kskwn.de 9 2026-04-16 2026-09-08 ok
newsletter.kskwn.de 5 2026-05-08 2026-09-05 ok
qr.kskwn.de 12 2026-04-28 2026-08-26 ok
www.kskwn.de 4 2026-03-27 2026-09-12 ok

Programmatic access, with DNS A records: API GET /v1/hosts/kskwn.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/kskwn.de.