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.

4 hosts · 247 ms

HostCertsFirst seenLast seenDNS
sbginc.us 3 2026-06-07 2026-08-16 ok
www.sbginc.us 3 2026-06-07 2026-08-16 ok
pay.sbginc.us 3 2026-06-08 2026-08-08 ok
www.pay.sbginc.us 3 2026-06-08 2026-08-08 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/sbginc.us (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/sbginc.us.