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.

10 hosts · 331 ms

HostCertsFirst seenLast seenDNS
blitzsport.com 25 2026-05-02 2026-10-01 ok
*.blitzsport.com 20 2026-06-04 2026-10-01 —
mcprod.blitzsport.com 5 2026-05-02 2026-08-30 ok
medwaypractice.blitzsport.com 1 2026-07-08 2026-07-08 ok
secure.blitzsport.com 4 2026-04-14 2026-09-01 ok
mcstaging.blitzsport.com 5 2026-06-15 2026-09-28 ok
blog.blitzsport.com 3 2026-04-16 2026-08-17 ok
cdn.blitzsport.com 1 2026-01-11 2026-01-11 ok
apollo.blitzsport.com 2 2026-02-22 2026-06-14 ok
www.blitzsport.com 5 2026-05-14 2026-10-01 ok

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