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.

4 hosts · 351 ms

HostCertsFirst seenLast seen
go-yubi.com 6 2025-06-13 2026-09-02
*.go-yubi.com 36 2025-06-13 2026-10-05
developer.go-yubi.com 20 2026-04-28 2026-09-29
trust.go-yubi.com 9 2026-05-17 2026-09-13

Programmatic access: API GET /v1/hosts/go-yubi.com (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/go-yubi.com.