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.

5 hosts · 304 ms

HostCertsFirst seenLast seenDNS
signsdirect.com 41 2026-04-22 2026-10-01 ok
*.signsdirect.com 29 2026-04-22 2026-10-01 —
mta-sts.signsdirect.com 5 2026-05-02 2026-09-01 ok
checkout.signsdirect.com 3 2026-06-15 2026-08-24 ok
www.signsdirect.com 15 2026-05-09 2026-09-04 ok

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