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.

7 hosts · 228 ms

HostCertsFirst seenLast seen
www.redflagdeals.com 5 2026-05-31 2026-09-28
rfd-staging1.www.redflagdeals.com 5 2026-05-31 2026-09-28
rfd-staging2.www.redflagdeals.com 5 2026-05-31 2026-09-28
rfd-staging3.www.redflagdeals.com 5 2026-05-31 2026-09-28
rfd-staging4.www.redflagdeals.com 5 2026-05-31 2026-09-28
staging.www.redflagdeals.com 5 2026-05-31 2026-09-28
*.eph-staging.www.redflagdeals.com 5 2026-05-31 2026-09-28

Programmatic access: API GET /v1/hosts/www.redflagdeals.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/www.redflagdeals.com.