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 · 312 ms

HostCertsFirst seenLast seenDNS
rumbleup.com 20 2025-08-04 2026-10-04 ok
*.rumbleup.com 4 2025-08-04 2026-09-02 —
funnel.rumbleup.com 10 2026-05-14 2026-09-10 ok
www.rumbleup.com 13 2026-04-09 2026-10-04 ok

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