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 · 227 ms

HostCertsFirst seenLast seen
tgtdf.com 2 2026-06-17 2026-06-17
oa.tgtdf.com 5 2025-12-03 2026-08-31
tgtmail.tgtdf.com 6 2025-12-03 2026-08-31
o365smtp.tgtdf.com 5 2025-12-03 2026-08-31
autodiscover.tgtdf.com 5 2025-12-03 2026-08-31

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