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 · 308 ms

HostCertsFirst seenLast seen
nextmatter.com 16 2026-05-04 2026-09-13
*.nextmatter.com 3 2025-11-03 2026-10-03
*.core.nextmatter.com 2 2026-03-07 2026-07-23
tesco.nextmatter.com 5 2026-05-01 2026-08-29
help.nextmatter.com 14 2026-05-10 2026-09-07
status.nextmatter.com 5 2026-05-24 2026-09-25
trust.nextmatter.com 6 2026-06-02 2026-07-31
www.nextmatter.com 6 2026-05-18 2026-09-13

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