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.

3 hosts · 332 ms

HostCertsFirst seenLast seenDNS
mailculture.de 2 2025-09-29 2026-08-29 ok
mta-sts.mailculture.de 5 2026-05-21 2026-09-19 ok
www.mailculture.de 2 2025-09-29 2026-08-29 ok

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