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.

7 hosts · 256 ms

HostCertsFirst seenLast seen
colleague.ai 10 2025-10-26 2026-09-26
*.colleague.ai 5 2025-10-26 2026-09-26
blog.colleague.ai 5 2026-05-09 2026-09-05
edeval.colleague.ai 1 2025-10-17 2025-10-17
www.colleague.ai 5 2026-05-09 2026-09-04
pay.colleague.ai 10 2026-06-01 2026-09-27
community.colleague.ai 12 2026-04-15 2026-09-13

Programmatic access: API GET /v1/hosts/colleague.ai (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/colleague.ai.