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.

7 hosts · 278 ms

HostCertsFirst seenLast seenDNS
southwestdebit.com 12 2026-04-30 2026-09-21 ok
*.southwestdebit.com 12 2026-04-30 2026-09-21 —
email.southwestdebit.com 2 2026-05-13 2026-05-13 nxdomain
info.southwestdebit.com 12 2026-05-20 2026-09-15 ok
app.southwestdebit.com 12 2025-09-11 2026-09-01 ok
pages.southwestdebit.com 2 2026-05-13 2026-05-13 ok
www.southwestdebit.com 9 2026-05-17 2026-09-13 ok

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