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.

5 hosts · 322 ms

HostCertsFirst seenLast seenDNS
kkco.com.tw 18 2026-04-17 2026-10-06 ok
*.kkco.com.tw 18 2026-04-17 2026-10-06 —
wifi-portal.kkco.com.tw 1 2026-01-19 2026-01-19 nxdomain
www.wifi-portal.kkco.com.tw 1 2026-01-19 2026-01-19 nxdomain
status.kkco.com.tw 1 2026-09-06 2026-09-06 ok

Programmatic access, with DNS A records: API GET /v1/hosts/kkco.com.tw (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/kkco.com.tw.