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.

5 hosts · 348 ms

HostCertsFirst seenLast seenDNS
quadlockcase.co.uk 13 2026-05-15 2026-09-25 ok
clk.quadlockcase.co.uk 2 2026-10-06 2026-10-06 ok
sms.quadlockcase.co.uk 10 2026-05-10 2026-09-05 ok
account.quadlockcase.co.uk 14 2026-05-26 2026-10-04 ok
www.quadlockcase.co.uk 8 2026-05-15 2026-09-11 ok

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