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 · 234 ms

HostCertsFirst seenLast seenDNS
futurefoam.com 8 2025-09-02 2026-10-03 ok
*.futurefoam.com 8 2025-09-02 2026-10-03 —

Programmatic access, with DNS A records: API GET /v1/hosts/futurefoam.com (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/futurefoam.com.