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 · 295 ms

HostCertsFirst seenLast seenDNS
test.verizon.com 165 2025-09-04 2026-10-01 nodata
87211.test.verizon.com 1 2026-07-21 2026-07-21 nxdomain
6321.test.verizon.com 1 2026-07-21 2026-07-21 nxdomain
8441.test.verizon.com 3 2026-08-07 2026-08-07 nxdomain
2303d1.test.verizon.com 1 2026-07-17 2026-07-17 nxdomain
22312.test.verizon.com 1 2026-07-17 2026-07-17 nxdomain
8342.test.verizon.com 1 2026-08-07 2026-08-07 nxdomain
5323542.test.verizon.com 2 2026-07-27 2026-07-27 nxdomain
3213.test.verizon.com 1 2026-07-24 2026-07-24 nxdomain
5049a43.test.verizon.com 3 2026-07-17 2026-07-17 nxdomain
65234.test.verizon.com 1 2026-07-17 2026-07-17 nxdomain
7234.test.verizon.com 1 2026-07-24 2026-07-24 nxdomain
54374.test.verizon.com 1 2026-07-21 2026-07-21 nxdomain
523467.test.verizon.com 1 2026-07-24 2026-07-24 nxdomain

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