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 · 274 ms

HostCertsFirst seenLast seen
autio.com 5 2026-05-15 2026-09-18
*.autio.com 2 2026-03-07 2026-07-23
staging.autio.com 5 2026-05-22 2026-09-19
stagingai.autio.com 5 2026-04-23 2026-08-21
openai.autio.com 5 2026-05-07 2026-09-05
link.autio.com 4 2026-06-10 2026-10-08
app.autio.com 4 2026-04-30 2026-09-22
affiliates.autio.com 2 2026-04-11 2026-09-11
partners.autio.com 2 2026-10-07 2026-10-07
support.autio.com 12 2026-05-19 2026-09-14
www.autio.com 5 2026-05-10 2026-09-12
acme-sandbox.autio.com 3 2026-09-22 2026-09-22

Programmatic access: API GET /v1/hosts/autio.com (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/autio.com.