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.

3 hosts · 275 ms

Download CSV
HostCertsFirst seenLast seen
m.service.healthspan.co.uk 2 2025-07-15 2026-06-15
res.service.healthspan.co.uk 2 2025-07-15 2026-06-15
t.service.healthspan.co.uk 2 2025-07-15 2026-06-15

Programmatic access: API GET /v1/hosts/service.healthspan.co.uk (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/service.healthspan.co.uk.