Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

3 hosts · 229 ms

HostCertsFirst seenLast seenDNS
mtacc.info 1 2026-05-05 2026-05-05 nodata
*.mtacc.info 1 2026-05-05 2026-05-05 —
autodiscover.mtacc.info 1 2025-08-12 2025-08-12 ok

Programmatic access, with DNS A records: API GET /v1/hosts/mtacc.info (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/mtacc.info.