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 · 340 ms

HostCertsFirst seenLast seenDNS
inextenso-es.com 2 2026-02-27 2026-08-16 ok
mta-sts.inextenso-es.com 5 2026-04-29 2026-08-27 ok
www.inextenso-es.com 2 2026-02-27 2026-08-16 ok

Programmatic access, with DNS A records: API GET /v1/hosts/inextenso-es.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/inextenso-es.com.