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 · 209 ms

HostCertsFirst seenLast seenDNS
cloud.rewards.myhap.org 3 2025-11-04 2026-09-21 ok
image.rewards.myhap.org 79 2025-11-04 2026-01-27 servfail
click.rewards.myhap.org 3 2025-11-04 2026-09-20 ok
view.rewards.myhap.org 4 2025-11-04 2026-09-20 ok

Programmatic access, with DNS A records: API GET /v1/hosts/rewards.myhap.org (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/rewards.myhap.org.