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.

12 hosts · 314 ms

HostCertsFirst seenLast seen
diennea.com 9 2025-10-07 2026-10-06
*.diennea.com 11 2025-10-07 2026-10-06
test123.diennea.com 4 2026-04-29 2026-05-15
test234.diennea.com 2 2026-05-18 2026-05-18
test999.diennea.com 9 2026-05-18 2026-10-02
webexperience-lab.diennea.com 3 2026-07-29 2026-09-28
jsm.service.diennea.com 2 2026-04-17 2026-09-17
support.service.diennea.com 3 2026-04-17 2026-09-17
servicedesk.diennea.com 3 2026-04-17 2026-09-17
jsm.diennea.com 3 2026-04-17 2026-09-17
hrnews.diennea.com 5 2026-05-11 2026-08-28
support.diennea.com 3 2026-06-24 2026-08-23

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