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.

9 hosts · 175 ms

HostCertsFirst seenLast seen
qualitia.co.jp 5 2026-04-26 2026-09-13
*.qualitia.co.jp 5 2026-04-26 2026-09-13
ahupdate.qualitia.co.jp 3 2026-09-18 2026-10-02
*.i.qualitia.co.jp 5 2026-05-10 2026-09-13
tls-checker.biztool.qualitia.co.jp 2 2026-03-12 2026-07-28
info.qualitia.co.jp 9 2026-04-14 2026-09-11
ahup.qualitia.co.jp 2 2026-10-02 2026-10-02
dev.sales.qualitia.co.jp 5 2026-05-21 2026-09-18
dev.qualitia.co.jp 5 2026-04-29 2026-08-28

Programmatic access: API GET /v1/hosts/qualitia.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/qualitia.co.jp.