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 · 307 ms

HostCertsFirst seenLast seenDNS
amerifast.com 21 2026-05-03 2026-10-06 ok
*.amerifast.com 17 2026-05-03 2026-10-06 —
www.amerifast.com 4 2026-05-28 2026-09-29 ok

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