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.

11 hosts · 307 ms

HostCertsFirst seenLast seenDNS
franklinsports.com 22 2026-01-15 2026-10-01 ok
*.franklinsports.com 22 2026-01-15 2026-10-01 —
w132.franklinsports.com 3 2025-09-07 2026-08-08 nodata
ad.franklinsports.com 1 2026-01-28 2026-01-28 nxdomain
FSBI01.ad.franklinsports.com 1 2026-01-28 2026-01-28 —
FSAPPS01.ad.franklinsports.com 1 2026-01-28 2026-01-28 —
FSBI02.ad.franklinsports.com 1 2026-01-28 2026-01-28 —
link.franklinsports.com 8 2026-04-21 2026-08-17 ok
stories.franklinsports.com 4 2026-06-12 2026-08-10 ok
status.franklinsports.com 9 2026-06-01 2026-09-28 ok
support.franklinsports.com 15 2026-06-03 2026-09-29 ok

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