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 · 288 ms

HostCertsFirst seenLast seenDNS
hayaregi.com 6 2025-08-27 2026-09-30 ok
stg.hayaregi.com 5 2026-05-27 2026-09-30 servfail
www.hayaregi.com 5 2026-05-27 2026-09-30 ok

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