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 · 250 ms

HostCertsFirst seenLast seen
sidefx.com 1 2026-04-22 2026-04-22
*.sidefx.com 1 2026-04-22 2026-04-22
media.sidefx.com 2 2026-05-07 2026-10-07
static.sidefx.com 2 2026-05-07 2026-10-07
alb-origin.sidefx.com 1 2026-05-29 2026-05-29

Programmatic access: API GET /v1/hosts/sidefx.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/sidefx.com.