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.

22 hosts · 282 ms

HostCertsFirst seenLast seenDNS
restless.co.uk 60 2026-04-11 2026-10-05 ok
*.restless.co.uk 66 2026-02-26 2026-10-05 —
games-beta.restless.co.uk 1 2026-09-25 2026-09-25 ok
games.beta.restless.co.uk 1 2026-09-25 2026-09-25 ok
staging.restless.co.uk 3 2026-02-26 2026-10-03 ok
auth-staging.restless.co.uk 10 2026-04-24 2026-08-21 ok
*.events-staging.restless.co.uk 10 2026-05-30 2026-09-25 —
accounts-staging.restless.co.uk 2 2026-06-05 2026-06-05 ok
*.staging.restless.co.uk 29 2026-02-26 2026-10-03 —
*.events.staging.restless.co.uk 14 2026-05-04 2026-08-30 —
dating.restless.co.uk 10 2026-05-06 2026-09-03 ok
www.dating.restless.co.uk 10 2026-05-06 2026-09-03 ok
auth.restless.co.uk 10 2026-04-25 2026-08-22 ok
links-staging.email.restless.co.uk 12 2026-04-18 2026-08-15 ok
links.email.restless.co.uk 8 2026-04-14 2026-08-11 ok
trip.restless.co.uk 2 2026-03-16 2026-08-16 ok
labs.restless.co.uk 9 2026-07-04 2026-10-01 ok
tools.restless.co.uk 2 2026-03-18 2026-08-18 ok
*.events.restless.co.uk 42 2026-04-11 2026-10-05 —
accounts.restless.co.uk 8 2026-02-25 2026-09-01 ok
auth-alex-test.restless.co.uk 10 2026-04-30 2026-08-27 ok
www.restless.co.uk 2 2026-04-18 2026-09-18 ok

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