Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

40 hosts · 416 ms

HostCertsFirst seenLast seenDNS
open-xchange.com 18 2026-02-11 2026-10-05 ok
*.open-xchange.com 8 2026-02-11 2026-10-05 —
qa.open-xchange.com 8 2026-02-11 2026-10-05 nodata
*.qa.open-xchange.com 8 2026-02-11 2026-10-05 —
gitlab.open-xchange.com 5 2026-06-19 2026-08-18 ok
*.gitlab.open-xchange.com 5 2026-06-19 2026-08-18 —
infohub.open-xchange.com 8 2026-04-19 2026-08-15 ok
id.open-xchange.com 1 2026-04-27 2026-04-27 ok
opencloud.open-xchange.com 4 2026-05-21 2026-10-05 ok
*.opencloud.open-xchange.com 4 2026-05-21 2026-10-05 —
brcloud.open-xchange.com 5 2026-05-08 2026-09-05 ok
appsuite.open-xchange.com 5 2026-05-21 2026-10-05 ok
dav-appsuite.open-xchange.com 1 2026-09-25 2026-09-25 ok
*.appsuite.open-xchange.com 5 2026-05-21 2026-10-05 —
blog.open-xchange.com 10 2026-06-02 2026-09-19 ok
email.open-xchange.com 12 2026-06-02 2026-09-19 ok
testrail.open-xchange.com 5 2026-05-04 2026-10-05 nodata
idm.open-xchange.com 3 2026-05-12 2026-09-24 ok
jira.atlassian.open-xchange.com 2 2026-03-31 2026-08-31 ok
info.open-xchange.com 13 2026-05-31 2026-09-19 ok
demo.open-xchange.com 8 2026-04-11 2026-09-08 ok
*.demo.open-xchange.com 8 2026-04-11 2026-09-08 —
vdp.open-xchange.com 15 2026-04-29 2026-09-02 ok
brands.open-xchange.com 5 2026-05-31 2026-05-31 ok
pages.open-xchange.com 5 2026-06-19 2026-08-18 ok
*.pages.open-xchange.com 5 2026-06-19 2026-08-18 —
careers.open-xchange.com 1 2025-08-26 2025-08-26 ok
talents.open-xchange.com 7 2026-06-01 2026-06-01 ok
alcatraz-dus.open-xchange.com 2 2026-05-12 2026-05-12 ok
mssql.it.open-xchange.com 1 2026-01-13 2026-01-13 nxdomain
appsuite-test.open-xchange.com 5 2026-05-21 2026-10-05 ok
dav-appsuite-test.open-xchange.com 1 2026-09-25 2026-09-25 nodata
*.appsuite-test.open-xchange.com 5 2026-05-21 2026-10-05 —
registry-test.open-xchange.com 6 2026-04-25 2026-09-03 ok
*.registry-test.open-xchange.com 6 2026-04-25 2026-09-03 —
pbsr01-dev.open-xchange.com 5 2026-05-02 2026-08-31 ok
www.open-xchange.com 10 2026-06-01 2026-09-19 ok
sandbox.open-xchange.com 5 2026-05-28 2026-09-25 ok
registry.open-xchange.com 6 2026-04-25 2026-09-14 ok
*.registry.open-xchange.com 6 2026-04-25 2026-09-14 —

Programmatic access, with DNS A records: API GET /v1/hosts/open-xchange.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/open-xchange.com.