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 · 279 ms

HostCertsFirst seenLast seenDNS
protiviti.it 3 2025-10-10 2026-07-21 ok
skills.protiviti.it 2 2026-03-02 2026-07-15 ok
www.protiviti.it 3 2025-10-10 2026-07-21 ok

Programmatic access, with DNS A records: API GET /v1/hosts/protiviti.it (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/protiviti.it.