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.

32 hosts · 302 ms

HostCertsFirst seenLast seen
*.cyber.go.jp 1 2026-03-10 2026-03-10
stg.cyber.go.jp 4 2025-11-12 2026-08-17
stg01.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
gov-stg01.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
stub-api.stg01.kmrk.cyber.go.jp 1 2026-10-08 2026-10-08
cognito.stg01.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
stg02.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
gov-stg02.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
cognito.stg02.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
cognito-alt.stg02.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
stg03.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
gov-stg03.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
cognito.stg03.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
cognito-alt.stg03.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
stg04.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
gov-stg04.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
cognito.stg04.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
stg05.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
gov-stg05.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
cognito.stg05.kmrk.cyber.go.jp 1 2026-04-20 2026-04-20
security-portal.cyber.go.jp 5 2025-11-21 2026-09-27
*.security-portal.cyber.go.jp 2 2025-11-21 2025-11-21
junction.cyber.go.jp 1 2026-02-13 2026-02-13
p4s.cyber.go.jp 1 2026-04-20 2026-04-20
cognito.p4s.cyber.go.jp 1 2026-04-20 2026-04-20
cognito-alt.p4s.cyber.go.jp 1 2026-04-20 2026-04-20
gov.p4s.cyber.go.jp 1 2026-04-20 2026-04-20
chat.cyber.go.jp 1 2025-12-05 2025-12-05
chat-uat.cyber.go.jp 1 2026-07-10 2026-07-10
www.cyber.go.jp 3 2026-03-16 2026-08-17
dev.www.cyber.go.jp 4 2025-10-23 2026-08-18
stg.dev.www.cyber.go.jp 3 2026-03-17 2026-08-18

Programmatic access: API GET /v1/hosts/cyber.go.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/cyber.go.jp.