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.

4 hosts · 338 ms

HostCertsFirst seenLast seenDNS
threebestrated.co.uk 21 2026-04-07 2026-08-21 ok
*.threebestrated.co.uk 16 2026-04-24 2026-08-21 —
mail.threebestrated.co.uk 5 2026-05-11 2026-09-10 ok
www.threebestrated.co.uk 5 2026-04-07 2026-08-05 ok

Programmatic access, with DNS A records: API GET /v1/hosts/threebestrated.co.uk (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/threebestrated.co.uk.