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.

6 hosts · 217 ms

HostCertsFirst seenLast seen
skylight.org 52 2026-05-01 2026-10-04
*.skylight.org 14 2026-05-01 2026-09-24
blog.skylight.org 6 2026-06-13 2026-08-11
api.skylight.org 20 2026-05-01 2026-10-04
prayerwrap.skylight.org 2 2026-05-11 2026-05-11
api-dev.skylight.org 10 2026-05-01 2026-08-27

Programmatic access: API GET /v1/hosts/skylight.org (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/skylight.org.