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.

24 hosts · 315 ms

HostCertsFirst seenLast seenDNS
fitonhealth.com 11 2026-05-24 2026-09-19 ok
*.fitonhealth.com 2 2025-08-25 2026-08-12 —
secure.fitonhealth.com 5 2026-03-24 2026-09-06 ok
www.secure.fitonhealth.com 3 2026-03-24 2026-09-06 nxdomain
secure-staging.fitonhealth.com 5 2026-04-03 2026-09-29 ok
api-staging.fitonhealth.com 2 2026-09-22 2026-09-22 ok
admin-api-staging.fitonhealth.com 4 2026-02-20 2026-10-04 ok
partners-api-staging.fitonhealth.com 4 2026-02-20 2026-10-04 ok
gateway-api-staging.fitonhealth.com 4 2026-02-20 2026-10-04 ok
admin-staging.fitonhealth.com 3 2026-04-03 2026-09-29 ok
partner-staging.fitonhealth.com 3 2026-01-09 2026-09-29 ok
sl-tracking.fitonhealth.com 4 2026-04-19 2026-08-17 ok
admin-api.fitonhealth.com 1 2026-10-02 2026-10-02 ok
partners-api.fitonhealth.com 3 2026-01-02 2026-10-02 ok
www.partners-api.fitonhealth.com 2 2026-01-02 2026-01-02 nxdomain
gateway-api.fitonhealth.com 1 2026-10-02 2026-10-02 ok
admin.fitonhealth.com 6 2026-03-10 2026-08-23 ok
www.admin.fitonhealth.com 2 2026-03-10 2026-08-23 nxdomain
integration.fitonhealth.com 2 2025-12-03 2025-12-16 ok
www.integration.fitonhealth.com 2 2025-12-03 2025-12-16 nxdomain
help.fitonhealth.com 8 2026-04-26 2026-08-22 ok
partner.fitonhealth.com 3 2026-04-08 2026-08-17 ok
reports.fitonhealth.com 3 2026-02-13 2026-10-05 ok
www.fitonhealth.com 8 2026-05-03 2026-08-30 ok

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