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 · 382 ms

HostCertsFirst seenLast seenDNS
jbtools.com 6 2025-10-01 2026-10-04 ok
*.jbtools.com 2 2025-10-04 2026-09-04 —
de.jbtools.com 2 2026-01-25 2026-06-23 ok
www.jbtools.com 4 2025-10-01 2026-10-04 ok

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