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 · 223 ms

HostCertsFirst seenLast seenDNS
nectar.sainsburys.co.uk 2 2025-07-04 2026-06-03 ok
*.nectar.sainsburys.co.uk 2 2025-07-04 2026-06-03 —
assets.nectar.sainsburys.co.uk 2 2025-08-01 2026-07-01 ok

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