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 · 276 ms

HostCertsFirst seenLast seen
nextmatter.ca 2 2026-03-08 2026-07-24
*.nextmatter.ca 1 2025-12-25 2025-12-25
data.core.cmhc-uat.nextmatter.ca 1 2026-02-04 2026-02-04
app.cmhc-uat.nextmatter.ca 1 2026-02-05 2026-02-05
*.cmhc-dev.nextmatter.ca 2 2025-12-17 2025-12-17
*.core.cmhc-dev.nextmatter.ca 1 2025-12-17 2025-12-17
www.nextmatter.ca 2 2026-03-08 2026-07-24

Programmatic access: API GET /v1/hosts/nextmatter.ca (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/nextmatter.ca.