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.

35 hosts · 971 ms

HostCertsFirst seenLast seenDNS
frontdoor.com 7 2025-08-27 2026-08-13 ok
*.frontdoor.com 9 2025-07-09 2026-07-13 —
prod-search01.frontdoor.com 2 2026-03-17 2026-08-17 ok
brand.frontdoor.com 1 2026-01-06 2026-01-06 ok
upgrade.frontdoor.com 2 2026-07-06 2026-07-06 ok
staging.upgrade.frontdoor.com 2 2026-02-15 2026-02-15 ok
test.upgrade.frontdoor.com 2 2026-02-15 2026-02-15 ok
dev.upgrade.frontdoor.com 2 2026-02-15 2026-02-15 ok
staging.frontdoor.com 5 2025-08-27 2026-08-13 ok
contractor.staging.frontdoor.com 2 2026-01-05 2026-01-05 nxdomain
www.staging.frontdoor.com 5 2025-08-27 2026-08-13 nxdomain
shopping.frontdoor.com 2 2026-07-06 2026-07-06 ok
staging.shopping.frontdoor.com 2 2026-07-06 2026-07-06 ok
test.shopping.frontdoor.com 2 2026-02-15 2026-02-15 ok
dev.shopping.frontdoor.com 2 2026-02-15 2026-02-15 ok
www.shopping.frontdoor.com 2 2026-01-05 2026-01-05 ok
sandbox.shopping.frontdoor.com 2 2026-07-06 2026-07-06 ok
di.frontdoor.com 4 2026-04-15 2026-07-13 ok
test.license-portal.frontdoor.com 2 2026-02-15 2026-02-15 nxdomain
dev.license-portal.frontdoor.com 2 2026-02-15 2026-02-15 nxdomain
pro.frontdoor.com 9 2025-07-09 2026-07-13 ok
staging.pro.frontdoor.com 9 2025-07-09 2026-07-13 ok
csp.pro.frontdoor.com 9 2025-07-09 2026-07-13 ok
staging.csp.pro.frontdoor.com 9 2025-07-09 2026-07-13 ok
test.csp.pro.frontdoor.com 2 2026-02-15 2026-02-15 ok
dev.csp.pro.frontdoor.com 2 2026-02-15 2026-02-15 ok
test.pro.frontdoor.com 2 2026-02-15 2026-02-15 ok
dev.pro.frontdoor.com 2 2026-02-15 2026-02-15 ok
www.pro.frontdoor.com 9 2025-07-09 2026-07-13 nxdomain
test.frontdoor.com 17 2025-08-27 2026-08-22 ok
www.test.frontdoor.com 5 2025-08-27 2026-08-13 nxdomain
dev.frontdoor.com 5 2025-08-27 2026-08-13 ok
*.dev.frontdoor.com 9 2025-07-09 2026-07-13 —
www.dev.frontdoor.com 5 2025-08-27 2026-08-13 nxdomain
www.frontdoor.com 5 2025-08-27 2026-08-13 ok

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