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.

5 hosts · 249 ms

HostCertsFirst seenLast seen
pockethealth.com 9 2026-04-13 2026-08-15
e.pockethealth.com 2 2026-03-06 2026-07-19
groove.pockethealth.com 5 2026-05-22 2026-09-20
go.pockethealth.com 8 2026-04-20 2026-08-16
www.pockethealth.com 8 2026-04-18 2026-08-14

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