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 · 352 ms

HostCertsFirst seenLast seenDNS
service.ryanairemails.com 1 2026-04-22 2026-04-22 ok
m4.services.ryanairemails.com 3 2025-08-21 2026-08-27 ok
res4.services.ryanairemails.com 3 2025-08-21 2026-08-27 ok
t4.services.ryanairemails.com 3 2025-08-21 2026-08-27 ok
m5.services.ryanairemails.com 3 2025-08-21 2026-08-27 ok
res5.services.ryanairemails.com 3 2025-08-21 2026-08-27 ok
t5.services.ryanairemails.com 3 2025-08-21 2026-08-27 ok

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