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 · 198 ms

HostCertsFirst seenLast seen
sainsburysenergy.com 3 2025-11-14 2025-12-10
auth.sainsburysenergy.com 4 2026-08-06 2026-10-05
email.sainsburysenergy.com 20 2026-04-22 2026-09-27
notrack.email.sainsburysenergy.com 5 2026-05-19 2026-10-08
assets.email.sainsburysenergy.com 4 2026-06-09 2026-10-06
l.info.sainsburysenergy.com 1 2026-02-17 2026-02-17
www.sainsburysenergy.com 3 2025-11-14 2025-12-10

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