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 · 267 ms

HostCertsFirst seenLast seenDNS
hotpads.com 3 2025-10-01 2026-08-24 ok
*.hotpads.com 3 2025-10-01 2026-08-24 —
help.hotpads.com 4 2026-04-14 2026-08-12 ok

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