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.

5 hosts · 206 ms

HostCertsFirst seenLast seen
assets.email.sanofi 4 2026-04-29 2026-09-29
cloud.news.email.sanofi 2 2026-01-25 2026-01-26
image.news.email.sanofi 2 2025-12-04 2026-02-02
click.news.email.sanofi 1 2025-11-06 2025-11-06
view.news.email.sanofi 1 2025-11-06 2025-11-06

Programmatic access: API GET /v1/hosts/email.sanofi (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/email.sanofi.