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.

14 hosts · 366 ms

HostCertsFirst seenLast seenDNS
steelers.com 5 2026-04-25 2026-08-23 ok
auth-id.steelers.com 2 2025-07-20 2026-06-20 ok
e.steelers.com 5 2026-02-26 2026-09-21 ok
www.e.steelers.com 3 2026-03-03 2026-09-21 nxdomain
staging.steelers.com 5 2026-06-17 2026-09-27 ok
suiteshop-staging.steelers.com 5 2026-06-17 2026-09-27 ok
customshop-staging.steelers.com 5 2026-06-17 2026-09-27 ok
mi.steelers.com 5 2026-04-29 2026-08-29 ok
shop.steelers.com 5 2026-05-26 2026-09-23 ok
beta-shop.steelers.com 5 2026-05-26 2026-09-23 ok
suiteshop.steelers.com 5 2026-05-26 2026-09-23 ok
customshop.steelers.com 5 2026-05-26 2026-09-23 ok
qr.steelers.com 4 2026-06-22 2026-08-13 ok
www.steelers.com 5 2026-04-25 2026-08-23 ok

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