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.

5 hosts · 332 ms

HostCertsFirst seenLast seenDNS
discoversora.com 7 2026-05-18 2026-09-21 ok
*.discoversora.com 4 2026-05-18 2026-09-21 —
pages.discoversora.com 14 2026-05-30 2026-09-25 ok
forms.discoversora.com 10 2026-05-15 2026-09-10 ok
www.discoversora.com 3 2026-06-08 2026-08-10 ok

Programmatic access, with DNS A records: API GET /v1/hosts/discoversora.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/discoversora.com.