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 · 276 ms

HostCertsFirst seenLast seenDNS
cloud.ultimatemedical-email.com 2 2026-04-27 2026-09-28 ok
image.ultimatemedical-email.com 4 2025-09-13 2026-10-01 ok
click.ultimatemedical-email.com 3 2025-09-08 2026-08-31 ok
view.ultimatemedical-email.com 3 2025-09-08 2026-08-26 ok

Programmatic access, with DNS A records: API GET /v1/hosts/ultimatemedical-email.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/ultimatemedical-email.com.