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.

6 hosts · 244 ms

HostCertsFirst seenLast seenDNS
regit.cars 17 2026-01-23 2026-09-07 ok
*.regit.cars 17 2026-01-23 2026-09-07 —
ngrok.regit.cars 4 2026-04-18 2026-08-16 ok
mail.regit.cars 3 2025-10-01 2026-10-05 ok
www.mail.regit.cars 3 2025-10-01 2026-10-05 ok
request.regit.cars 16 2026-05-13 2026-09-09 ok

Programmatic access, with DNS A records: API GET /v1/hosts/regit.cars (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/regit.cars.