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 · 225 ms

HostCertsFirst seenLast seen
synergie.com 5 2025-07-15 2026-08-24
www.synergie.com 7 2025-07-15 2026-09-27
contentfactory.synergie.com 2 2026-03-11 2026-07-27

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