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 · 283 ms

HostCertsFirst seenLast seenDNS
support.awscloud.etghq.com 3 2026-07-15 2026-07-20 ok
techtraining.etghq.com 5 2026-04-24 2026-08-22 ok
mta-sts.etghq.com 1 2025-12-03 2025-12-03 ok

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