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.

2 hosts · 153 ms

HostCertsFirst seenLast seen
img.unicafmail.org 16 2026-05-23 2026-09-18
r.unicafmail.org 3 2026-06-20 2026-09-08

Programmatic access: API GET /v1/hosts/unicafmail.org (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/unicafmail.org.