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.

3 hosts · 379 ms

HostCertsFirst seenLast seenDNS
tagmobile.com 14 2026-04-19 2026-10-06 ok
*.tagmobile.com 19 2025-11-20 2026-10-06 —
enrollment.tagmobile.com 1 2026-04-13 2026-04-13 ok

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