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.

2 hosts · 266 ms

HostCertsFirst seenLast seenDNS
erstepremier.cz 1 2026-02-17 2026-02-17 ok
www.erstepremier.cz 1 2026-02-17 2026-02-17 ok

Programmatic access, with DNS A records: API GET /v1/hosts/erstepremier.cz (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/erstepremier.cz.