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 · 293 ms

HostCertsFirst seenLast seenDNS
allyacademy.com 4 2025-09-05 2026-09-17 ok
www.allyacademy.com 4 2025-09-05 2026-09-17 ok
lb-www.allyacademy.com 1 2026-09-17 2026-09-17 nxdomain

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