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.

12 hosts · 242 ms

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HostCertsFirst seenLast seen
bestsecret.co.uk 10 2026-06-12 2026-10-15
*.bestsecret.co.uk 10 2026-06-12 2026-10-15
staging-release.bestsecret.co.uk 4 2026-06-17 2026-10-15
*.staging-release.bestsecret.co.uk 4 2026-06-17 2026-10-15
sgtm.bestsecret.co.uk 5 2026-04-23 2026-10-01
www.sgtm.bestsecret.co.uk 5 2026-05-08 2026-10-18
help.bestsecret.co.uk 1 2025-10-29 2025-10-29
www.help.bestsecret.co.uk 1 2025-10-29 2025-10-29
staging-master.bestsecret.co.uk 4 2026-06-17 2026-10-15
*.staging-master.bestsecret.co.uk 4 2026-06-17 2026-10-15
sgtm-dev.bestsecret.co.uk 5 2026-05-01 2026-10-12
www.sgtm-dev.bestsecret.co.uk 4 2026-05-30 2026-09-13

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