Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

10 hosts · 243 ms

HostCertsFirst seenLast seen
imagination.com 21 2025-09-10 2026-09-20
*.imagination.com 21 2025-09-10 2026-09-20
staging.imagination.com 1 2026-02-07 2026-02-07
fyi.imagination.com 4 2026-04-28 2026-10-08
itservicedesk.imagination.com 2 2026-04-21 2026-04-21
1pass.imagination.com 2 2026-05-03 2026-05-03
insights.imagination.com 12 2026-04-21 2026-06-19
test.imagination.com 1 2026-04-28 2026-04-28
images.test.imagination.com 1 2026-04-28 2026-04-28
assets.test.imagination.com 3 2026-06-01 2026-09-14

Programmatic access: API GET /v1/hosts/imagination.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/imagination.com.