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.

12 hosts · 275 ms

HostCertsFirst seenLast seenDNS
applecard.apple 4 2026-04-23 2026-09-29 ok
email.post-service.applecard.apple 9 2026-05-10 2026-10-04 ok
cloud.mail.applecard.apple 1 2026-09-22 2026-09-22 ok
image.mail.applecard.apple 18 2026-09-22 2026-09-30 ok
click.mail.applecard.apple 1 2026-09-22 2026-09-22 ok
view.mail.applecard.apple 1 2026-09-22 2026-09-22 ok
learn.applecard.apple 17 2026-04-27 2026-09-27 ok
offers.applecard.apple 17 2026-04-27 2026-09-27 ok
post.applecard.apple 4 2026-04-23 2026-09-29 ok
email.post.applecard.apple 9 2026-05-10 2026-10-04 ok
clicks.post.applecard.apple 9 2026-05-10 2026-10-04 ok
www.applecard.apple 4 2026-04-23 2026-09-29 ok

Programmatic access, with DNS A records: API GET /v1/hosts/applecard.apple (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/applecard.apple.