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 · 254 ms

HostCertsFirst seenLast seenDNS
strauss.nl 5 2026-04-21 2026-10-07 ok
www-qa.strauss.nl 6 2026-05-05 2026-10-07 ok
www-sta.strauss.nl 6 2026-05-05 2026-10-07 ok
help.strauss.nl 7 2026-04-22 2026-09-27 ok
www-dev.strauss.nl 6 2026-05-05 2026-10-07 ok
www.strauss.nl 5 2026-04-21 2026-10-07 ok

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