Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

14 hosts · 315 ms

HostCertsFirst seenLast seenDNS
kleos.io 18 2026-05-19 2026-09-22 ok
*.kleos.io 17 2026-05-19 2026-09-22 —
api.kleos.io 12 2026-06-03 2026-10-01 ok
*.api.kleos.io 18 2026-06-03 2026-10-01 —
app.kleos.io 13 2026-06-01 2026-09-29 ok
*.app.kleos.io 13 2026-06-01 2026-09-29 —
docs.kleos.io 13 2026-06-03 2026-09-30 ok
cis.kleos.io 4 2026-06-03 2026-06-03 ok
careers.kleos.io 10 2026-06-03 2026-09-23 ok
partners.kleos.io 10 2026-06-03 2026-09-29 ok
status.kleos.io 3 2026-06-15 2026-08-13 ok
trust.kleos.io 9 2026-06-02 2026-09-28 ok
fw.kleos.io 8 2026-06-03 2026-09-29 ok
www.kleos.io 2 2026-05-20 2026-05-20 ok

Programmatic access, with DNS A records: API GET /v1/hosts/kleos.io (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/kleos.io.