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.

14 hosts · 286 ms

HostCertsFirst seenLast seenDNS
seekinghealth.com 36 2026-04-16 2026-09-25 ok
*.seekinghealth.com 29 2026-04-16 2026-09-14 —
a1.seekinghealth.com 4 2026-04-17 2026-08-15 ok
education.seekinghealth.com 16 2026-05-04 2026-08-30 ok
shop.seekinghealth.com 5 2026-04-22 2026-08-22 ok
staging-shopify-app.seekinghealth.com 5 2026-05-07 2026-09-04 ok
resources.seekinghealth.com 18 2026-05-25 2026-10-02 ok
webhooks.seekinghealth.com 5 2026-05-09 2026-09-06 ok
formulations.seekinghealth.com 4 2026-04-17 2026-08-15 ok
staging-formulations.seekinghealth.com 4 2026-04-17 2026-08-15 ok
partners.seekinghealth.com 18 2026-04-20 2026-10-02 ok
support.seekinghealth.com 9 2026-05-18 2026-09-13 ok
partnersupport.seekinghealth.com 11 2026-05-27 2026-09-22 ok
www.seekinghealth.com 12 2026-05-17 2026-09-24 ok

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