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.

31 hosts · 265 ms

HostCertsFirst seenLast seen
safeopt.com 10 2026-05-11 2026-09-07
*.cdn1.safeopt.com 2 2025-09-04 2026-08-05
unsub-dev1.safeopt.com 3 2026-05-18 2026-08-31
manage-dev1.safeopt.com 3 2026-05-18 2026-09-06
offer-dev1.safeopt.com 4 2026-05-26 2026-09-14
*.offer-dev1.safeopt.com 4 2026-05-26 2026-09-14
unsub-dev2.safeopt.com 3 2026-05-18 2026-09-01
manage-dev2.safeopt.com 3 2026-05-18 2026-09-03
offer-dev2.safeopt.com 4 2026-04-24 2026-10-03
*.offer-dev2.safeopt.com 4 2026-04-24 2026-10-03
unsub-dev3.safeopt.com 3 2026-05-18 2026-09-05
manage-dev3.safeopt.com 3 2026-05-18 2026-08-31
offer-dev3.safeopt.com 5 2026-04-28 2026-10-05
*.offer-dev3.safeopt.com 5 2026-04-28 2026-10-05
unsub.safeopt.com 3 2026-05-18 2026-09-02
manage.safeopt.com 3 2026-05-18 2026-09-02
unsub-staging.safeopt.com 3 2026-05-18 2026-09-01
manage-staging.safeopt.com 3 2026-05-18 2026-09-01
offer-staging.safeopt.com 6 2026-04-21 2026-09-30
*.offer-staging.safeopt.com 6 2026-04-21 2026-09-30
minty-staging.safeopt.com 3 2026-05-18 2026-09-02
click.safeopt.com 1 2026-05-19 2026-05-19
cdn.safeopt.com 7 2025-09-04 2026-09-17
dev1.cdn.safeopt.com 4 2026-06-03 2026-09-19
dev2.cdn.safeopt.com 3 2026-05-31 2026-09-21
dev3.cdn.safeopt.com 3 2026-05-26 2026-09-09
staging.cdn.safeopt.com 3 2026-05-31 2026-09-17
offer.safeopt.com 3 2026-04-29 2026-08-16
*.offer.safeopt.com 3 2026-04-29 2026-08-16
www.safeopt.com 16 2026-06-03 2026-09-30
minty.safeopt.com 3 2026-05-18 2026-09-02

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