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.

8 hosts · 252 ms

HostCertsFirst seenLast seen
id.hyakugo.co.jp 1 2026-06-19 2026-06-19
stg.hyakugo.co.jp 4 2026-08-31 2026-08-31
id-stg.hyakugo.co.jp 2 2026-04-08 2026-09-08
*.stg.hyakugo.co.jp 4 2026-08-31 2026-08-31
sp.hyakugo.co.jp 1 2026-05-11 2026-05-11
www.hyakugo.co.jp 1 2025-12-16 2025-12-16
test-www.hyakugo.co.jp 4 2026-08-31 2026-09-11
*.test-www.hyakugo.co.jp 4 2026-08-31 2026-09-11

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