Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

3 hosts · 296 ms

HostCertsFirst seenLast seen
cliffordchance.co.uk 1 2026-09-30 2026-09-30
*.cliffordchance.co.uk 1 2026-09-30 2026-09-30
mta-sts.cliffordchance.co.uk 1 2025-12-30 2025-12-30

Programmatic access: API GET /v1/hosts/cliffordchance.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/cliffordchance.co.uk.