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.

16 hosts · 258 ms

HostCertsFirst seenLast seen
hytest.com 2 2025-10-09 2026-09-09
secure.hytest.com 2 2025-09-22 2026-06-08
www.secure.hytest.com 1 2025-09-22 2025-09-22
stg.hytest.com 22 2026-05-25 2026-09-20
loadteststg.hytest.com 10 2026-05-26 2026-09-21
cloud.email.hytest.com 1 2026-02-08 2026-02-08
image.email.hytest.com 4 2026-03-30 2026-09-29
click.email.hytest.com 1 2026-02-08 2026-02-08
view.email.hytest.com 1 2026-02-08 2026-02-08
admin.hytest.com 1 2025-09-22 2025-09-22
dms.hytest.com 1 2025-09-22 2025-09-22
www.hytest.com 16 2026-05-07 2026-09-02
safety.hytest.com 2 2025-06-29 2026-05-30
stg.safety.hytest.com 12 2026-05-02 2026-08-28
loadteststg.safety.hytest.com 20 2026-05-09 2026-09-04
www.safety.hytest.com 12 2026-04-22 2026-08-18

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