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.

4 hosts · 372 ms

HostCertsFirst seenLast seenDNS
cloud.email.a1.rs 1 2026-02-03 2026-02-03 ok
image.email.a1.rs 5 2026-04-09 2026-09-21 ok
click.email.a1.rs 1 2026-02-03 2026-02-03 ok
view.email.a1.rs 1 2026-02-03 2026-02-03 ok

Programmatic access, with DNS A records: API GET /v1/hosts/email.a1.rs (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/email.a1.rs.