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 · 212 ms

HostCertsFirst seenLast seen
go.public.resource.verizon.com 3 2025-11-25 2025-11-25
go.business.resource.verizon.com 3 2025-10-29 2026-01-26

Programmatic access: API GET /v1/hosts/resource.verizon.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/resource.verizon.com.