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.

13 hosts · 303 ms

HostCertsFirst seenLast seenDNS
haystack.tv 2 2025-07-17 2026-06-17 ok
*.haystack.tv 2 2025-08-06 2026-07-07 —
cdn2.haystack.tv 2 2025-07-11 2026-06-10 ok
img.haystack.tv 1 2026-01-01 2026-01-01 ok
watch.haystack.tv 14 2026-05-24 2026-09-19 ok
experimentsapi.haystack.tv 2 2026-03-04 2026-07-20 ok
devapi.haystack.tv 2 2025-06-25 2026-05-26 ok
vpn.haystack.tv 2 2026-04-18 2026-09-18 nxdomain
notifications.haystack.tv 2 2025-07-19 2026-06-19 ok
experiments.haystack.tv 2 2026-03-04 2026-07-20 ok
payments.haystack.tv 10 2026-04-21 2026-08-17 ok
gbdev.haystack.tv 1 2025-12-04 2025-12-04 ok
www.haystack.tv 2 2025-07-17 2026-06-17 ok

Programmatic access, with DNS A records: API GET /v1/hosts/haystack.tv (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/haystack.tv.