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.

5 hosts · 198 ms

HostCertsFirst seenLast seen
tjmorris.co.uk 17 2026-04-14 2026-09-22
*.tjmorris.co.uk 18 2025-12-25 2026-09-22
meng.tjmorris.co.uk 1 2025-10-01 2025-10-01
www.meng.tjmorris.co.uk 1 2025-10-01 2025-10-01
helpdesk.tjmorris.co.uk 10 2026-05-16 2026-09-13

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