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.

3 hosts · 361 ms

HostCertsFirst seenLast seenDNS
deliverabilityninja.com 19 2026-04-10 2026-10-04 ok
app.deliverabilityninja.com 17 2026-04-19 2026-09-01 ok
www.deliverabilityninja.com 15 2026-04-10 2026-10-04 ok

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