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.

8 hosts · 325 ms

HostCertsFirst seenLast seenDNS
regalcinemas.com 16 2025-09-08 2026-09-29 ok
*.regalcinemas.com 16 2025-09-08 2026-09-29 —
regexpe01.regalcinemas.com 1 2025-11-03 2025-11-03 ok
www.regexpe01.regalcinemas.com 1 2025-11-03 2025-11-03 nxdomain
*.rge.regalcinemas.com 1 2025-12-15 2025-12-15 —
www.rge.regalcinemas.com 5 2026-05-11 2026-09-08 ok
leave.regalcinemas.com 2 2026-04-23 2026-08-15 ok
medialibrary.regalcinemas.com 1 2026-01-10 2026-01-10 ok

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