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 · 243 ms

HostCertsFirst seenLast seen
marketing.dssi.net 22 2026-04-21 2026-10-02
*.marketing.dssi.net 14 2026-04-22 2026-10-02

Programmatic access: API GET /v1/hosts/marketing.dssi.net (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/marketing.dssi.net.