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 · 271 ms

HostCertsFirst seenLast seenDNS
rebuildmastertech.com 20 2026-04-30 2026-09-23 ok
*.rebuildmastertech.com 11 2026-04-30 2026-09-17 —
www.rebuildmastertech.com 11 2026-05-28 2026-09-23 ok

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