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.

18 hosts · 259 ms

HostCertsFirst seenLast seenDNS
highbeam.co 6 2026-04-27 2026-08-23 ok
f.highbeam.co 6 2026-06-04 2026-09-30 ok
auth.staging.highbeam.co 10 2026-04-25 2026-08-22 ok
api.staging.highbeam.co 3 2026-05-08 2026-08-26 ok
v2.api.staging.highbeam.co 4 2026-05-20 2026-10-06 ok
app.staging.highbeam.co 4 2026-04-21 2026-10-01 ok
apply.staging.highbeam.co 2 2025-09-01 2026-08-02 ok
auth.highbeam.co 10 2026-04-24 2026-08-21 ok
api.highbeam.co 3 2026-06-01 2026-09-16 ok
v2.api.highbeam.co 3 2026-05-09 2026-08-21 ok
app.demo.highbeam.co 4 2026-04-21 2026-10-01 ok
app.highbeam.co 5 2026-04-21 2026-09-29 ok
app.staging.insights.highbeam.co 4 2026-04-21 2026-10-01 ok
app.insights.highbeam.co 5 2026-04-21 2026-09-29 ok
connect.highbeam.co 13 2026-05-22 2026-09-17 ok
*.app.review.highbeam.co 3 2026-05-14 2026-09-03 —
www.highbeam.co 10 2026-05-06 2026-09-01 ok
apply.highbeam.co 2 2025-09-14 2026-08-15 ok

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