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.

14 hosts · 326 ms

HostCertsFirst seenLast seenDNS
highbeam.com 29 2026-04-22 2026-10-06 ok
*.highbeam.com 10 2026-06-10 2026-10-06 —
luma.highbeam.com 4 2026-05-20 2026-09-08 ok
docs.luma.highbeam.com 1 2026-05-24 2026-05-24 nxdomain
*.preview.luma.highbeam.com 2 2026-07-01 2026-08-27 —
intelligence.highbeam.com 1 2026-09-07 2026-09-07 ok
admin.staging.highbeam.com 4 2026-04-21 2026-10-01 ok
architecture.ai.highbeam.com 1 2026-08-30 2026-08-30 ok
admin.highbeam.com 5 2026-04-21 2026-09-29 ok
kairo.highbeam.com 4 2026-04-17 2026-08-16 ok
lp.highbeam.com 4 2026-04-20 2026-08-23 ok
workflows.highbeam.com 9 2026-06-08 2026-10-04 ok
enrichment.highbeam.com 2 2026-09-07 2026-09-26 ok
www.highbeam.com 10 2026-04-22 2026-08-19 ok

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