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.

4 hosts · 184 ms

HostCertsFirst seenLast seen
cloud.hello.listnr.com 1 2026-02-06 2026-02-06
image.hello.listnr.com 4 2026-03-19 2026-09-20
click.hello.listnr.com 1 2026-02-06 2026-02-06
view.hello.listnr.com 1 2026-02-06 2026-02-06

Programmatic access: API GET /v1/hosts/hello.listnr.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/hello.listnr.com.