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 · 340 ms

HostCertsFirst seenLast seenDNS
electric-heatingcompany.co.uk 2 2025-07-15 2026-08-13 ok
staging.electric-heatingcompany.co.uk 2 2026-05-25 2026-05-25 nxdomain
control.electric-heatingcompany.co.uk 5 2026-05-01 2026-07-28 ok
mta-sts.electric-heatingcompany.co.uk 4 2026-04-10 2026-08-09 ok
www.electric-heatingcompany.co.uk 2 2025-07-15 2026-08-13 ok

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