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 · 289 ms

HostCertsFirst seenLast seenDNS
cynetlocums.com 17 2026-04-11 2026-10-06 ok
*.cynetlocums.com 6 2026-04-16 2026-10-06 —
helpdesk.cynetlocums.com 9 2026-05-31 2026-09-26 ok

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