Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

4 hosts · 146 ms

HostCertsFirst seenLast seen
cloud.pts.southwest.com 1 2026-10-06 2026-10-06
image.pts.southwest.com 2 2026-01-07 2026-05-23
click.pts.southwest.com 2 2026-04-27 2026-09-28
view.pts.southwest.com 1 2025-12-07 2025-12-07

Programmatic access: API GET /v1/hosts/pts.southwest.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/pts.southwest.com.