Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

9 hosts · 236 ms

HostCertsFirst seenLast seenDNS
*.test.nsldsfap.ed.gov 23 2026-04-14 2026-08-20 —
nslds-web.test.nsldsfap.ed.gov 5 2025-10-15 2026-09-25 ok
nslds-system-api.test.nsldsfap.ed.gov 5 2025-10-15 2026-09-25 ok
nslds-api.test.nsldsfap.ed.gov 5 2025-10-15 2026-09-25 ok
nslds-alation.test.nsldsfap.ed.gov 5 2025-10-15 2026-09-25 ok
nslds-cognos.test.nsldsfap.ed.gov 5 2025-10-15 2026-09-25 ok
*.apps.test.nsldsfap.ed.gov 4 2026-04-13 2026-08-10 —
console-openshift-console.apps.test.nsldsfap.ed.gov 4 2026-04-13 2026-08-10 nodata
oauth-openshift.apps.test.nsldsfap.ed.gov 4 2026-04-13 2026-08-10 nodata

Programmatic access, with DNS A records: API GET /v1/hosts/test.nsldsfap.ed.gov (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/test.nsldsfap.ed.gov.