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 · 271 ms

HostCertsFirst seenLast seenDNS
mail.kirayaka.co.jp 1 2026-02-17 2026-02-17 ok
www.mail.kirayaka.co.jp 1 2026-02-17 2026-02-17 nxdomain
loan.kirayaka.co.jp 2 2026-01-23 2026-01-23 ok
app.kirayaka.co.jp 2 2026-03-05 2026-09-07 ok
www.kirayaka.co.jp 1 2025-11-25 2025-11-25 ok

Programmatic access, with DNS A records: API GET /v1/hosts/kirayaka.co.jp (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/kirayaka.co.jp.