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.

5 hosts · 250 ms

HostCertsFirst seenLast seen
pulstar.us 3 2025-08-11 2026-08-11
ng.pulstar.us 1 2026-08-26 2026-08-26
www.ng.pulstar.us 1 2026-08-26 2026-08-26
mail.pulstar.us 4 2026-06-11 2026-10-11
www.pulstar.us 3 2025-08-11 2026-08-11

Programmatic access: API GET /v1/hosts/pulstar.us (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/pulstar.us.