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.

16 hosts · 281 ms

HostCertsFirst seenLast seenDNS
clarkinc.biz 31 2025-11-29 2026-09-14 ok
*.clarkinc.biz 31 2025-11-29 2026-09-14 —
click.clarkinc.biz 5 2026-04-22 2026-10-05 ok
mail.clarkinc.biz 5 2025-09-02 2026-06-16 ok
securemail.clarkinc.biz 2 2026-07-24 2026-07-24 ok
www.securemail.clarkinc.biz 2 2026-07-24 2026-07-24 nxdomain
dam.clarkinc.biz 2 2026-03-16 2026-08-16 ok
learn.clarkinc.biz 2 2025-11-05 2025-12-29 ok
www.learn.clarkinc.biz 2 2025-11-05 2025-12-29 nxdomain
tokenizer.clarkinc.biz 2 2026-04-19 2026-10-03 ok
www.tokenizer.clarkinc.biz 2 2026-04-19 2026-10-03 nxdomain
test.clarkinc.biz 4 2026-04-16 2026-08-15 nodata
*.test.clarkinc.biz 16 2026-04-16 2026-09-10 —
tokenizer.test.clarkinc.biz 1 2025-11-14 2025-11-14 ok
www.tokenizer.test.clarkinc.biz 1 2025-11-14 2025-11-14 nxdomain
*.dev.clarkinc.biz 12 2026-05-15 2026-09-10 —

Programmatic access, with DNS A records: API GET /v1/hosts/clarkinc.biz (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/clarkinc.biz.