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.

7 hosts · 263 ms

HostCertsFirst seenLast seenDNS
gohighway.com 4 2025-11-08 2026-09-01 ok
*.gohighway.com 4 2025-11-08 2026-09-01 —
staging.gohighway.com 2 2026-03-31 2026-08-31 ok
*.staging.gohighway.com 3 2025-11-16 2026-08-31 —
marketing.gohighway.com 10 2026-04-15 2026-08-11 ok
dev.gohighway.com 2 2026-03-30 2026-08-30 ok
*.dev.gohighway.com 3 2025-11-08 2026-08-30 —

Programmatic access, with DNS A records: API GET /v1/hosts/gohighway.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/gohighway.com.