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.

7 hosts · 306 ms

HostCertsFirst seenLast seenDNS
chessable.com 39 2026-05-12 2026-09-30 ok
*.chessable.com 39 2026-05-12 2026-09-30 —
*.sandbox2.chessable.com 20 2026-06-04 2026-09-30 —
mail.chessable.com 4 2026-04-15 2026-08-15 ok
shop.chessable.com 15 2026-04-10 2026-09-21 ok
support.chessable.com 8 2026-05-21 2026-09-16 ok
*.sandbox.chessable.com 20 2026-06-04 2026-09-30 —

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