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 · 286 ms

HostCertsFirst seenLast seenDNS
steuerfabi.de 6 2026-05-04 2026-09-05 ok
*.steuerfabi.de 2 2026-05-04 2026-05-04 —
mta-sts.steuerfabi.de 1 2026-07-26 2026-07-26 ok
www.steuerfabi.de 4 2026-07-03 2026-09-05 ok

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