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.

2 hosts · 256 ms

HostCertsFirst seenLast seen
www.stg.ausonpo-app.jp 1 2025-12-25 2025-12-25
www.ausonpo-app.jp 2 2025-08-05 2026-08-21

Programmatic access: API GET /v1/hosts/ausonpo-app.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/ausonpo-app.jp.