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.

7 hosts · 307 ms

HostCertsFirst seenLast seen
flexbox.cloud 8 2026-04-16 2026-08-28
*.flexbox.cloud 6 2026-04-18 2026-08-28
links.email.flexbox.cloud 5 2026-05-01 2026-08-30
cp.flexbox.cloud 1 2026-04-11 2026-04-11
help.flexbox.cloud 5 2026-05-02 2026-08-31
status.flexbox.cloud 4 2026-04-20 2026-08-19
www.flexbox.cloud 2 2026-04-16 2026-04-16

Programmatic access: API GET /v1/hosts/flexbox.cloud (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/flexbox.cloud.