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 · 288 ms

HostCertsFirst seenLast seenDNS
allybank.com 2 2025-12-09 2026-08-13 ok
m.allybank.com 1 2025-12-09 2025-12-09 ok
www.allybank.com 1 2025-12-09 2025-12-09 ok

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