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.

8 hosts · 250 ms

HostCertsFirst seenLast seen
joinhandshake.ai 11 2026-05-04 2026-09-09
*.joinhandshake.ai 11 2026-05-04 2026-09-09
rubrics-training.joinhandshake.ai 11 2026-06-02 2026-09-28
task-viewer.joinhandshake.ai 10 2026-06-06 2026-10-02
samples.joinhandshake.ai 13 2026-06-04 2026-10-01
anthropic-samples.joinhandshake.ai 9 2026-05-27 2026-09-22
rubric-samples.joinhandshake.ai 10 2026-05-15 2026-09-10
audio-samples.joinhandshake.ai 11 2026-05-24 2026-09-19

Programmatic access: API GET /v1/hosts/joinhandshake.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/joinhandshake.ai.