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.

73 hosts · 734 ms

HostCertsFirst seenLast seenDNS
cos.com 16 2026-02-04 2026-09-23 ok
link.testmailmca1.cos.com 5 2026-05-19 2026-09-16 ok
link.testmail1.cos.com 5 2026-05-03 2026-08-31 ok
link.testmailmca2.cos.com 5 2026-05-19 2026-09-16 ok
link.testmail2.cos.com 5 2026-05-03 2026-08-31 ok
media.cos.com 14 2026-02-04 2026-09-15 ok
login.eu.qa.cos.com 2 2026-01-22 2026-06-12 ok
sa.cos.com 6 2026-05-02 2026-08-30 ok
login.eu.acc.cos.com 2 2026-01-22 2026-06-12 ok
smfpd.cos.com 11 2026-06-04 2026-09-30 ok
link.mca.e.cos.com 4 2026-06-04 2026-10-02 ok
link.e.cos.com 5 2026-05-15 2026-09-12 ok
link.us.e.cos.com 14 2026-05-07 2026-09-16 ok
ae.cos.com 6 2026-05-02 2026-08-30 ok
link.mca.service.cos.com 4 2026-06-04 2026-10-02 ok
link.service.cos.com 4 2026-06-05 2026-10-02 ok
link.us.service.cos.com 15 2026-05-07 2026-09-17 ok
prod-content-storage.cos.com 14 2026-02-04 2026-09-15 ok
emarketing.cos.com 7 2025-08-29 2026-07-02 ok
th.cos.com 16 2025-07-28 2026-07-25 ok
*.th.cos.com 4 2026-03-09 2026-07-25 —
prod.th.cos.com 5 2026-04-29 2026-08-27 nodata
mcprod.th.cos.com 5 2026-04-29 2026-08-27 nodata
staging.th.cos.com 4 2026-04-09 2026-08-07 ok
uat.th.cos.com 2 2025-08-01 2026-07-02 nodata
api.cos.com 12 2026-02-06 2026-09-15 ok
t.email.cos.com 2 2026-03-01 2026-07-17 ok
rt1-t.autoemail.cos.com 2 2026-03-01 2026-07-17 ok
accc-cll.cos.com 3 2025-09-25 2026-07-28 nxdomain
wyfbm.cos.com 11 2026-05-21 2026-09-16 ok
news.in.cos.com 3 2026-04-25 2026-08-11 ok
prod-translation.cos.com 14 2026-02-04 2026-09-15 ok
aimco.cos.com 6 2026-05-08 2026-09-03 ok
prod-sitemap.cos.com 14 2026-02-04 2026-09-15 ok
career.cos.com 2 2025-09-25 2026-07-29 ok
prod-orders-updater.cos.com 14 2026-02-04 2026-09-15 ok
autodiscover.cos.com 1 2026-04-28 2026-04-28 ok
htakr.cos.com 8 2026-05-11 2026-09-06 ok
*.npr.cos.com 2 2025-07-15 2026-07-06 —
s.cos.com 6 2026-04-27 2026-08-25 ok
images.cos.com 14 2026-02-04 2026-09-15 ok
int-images.cos.com 6 2025-09-25 2026-07-29 ok
syt-images.cos.com 6 2025-09-25 2026-07-29 ok
prod-centra-orders.cos.com 10 2026-03-03 2026-09-15 ok
press.cos.com 2 2025-09-25 2026-07-29 ok
prod-customer-events.cos.com 14 2026-02-04 2026-09-15 ok
login.au.cos.com 2 2026-02-05 2026-06-20 ok
login.eu.cos.com 2 2026-01-09 2026-06-10 ok
login.eu.dev.cos.com 2 2026-01-22 2026-06-12 ok
kw.cos.com 6 2026-05-02 2026-08-30 ok
www.cos.com 14 2026-02-04 2026-09-15 ok
dev1-www.cos.com 2 2025-09-25 2025-09-25 nxdomain
dev2-www.cos.com 4 2026-05-21 2026-07-27 nodata
dev3-www.cos.com 4 2026-05-21 2026-07-27 nodata
qa-www.cos.com 6 2025-09-25 2026-07-29 ok
acc-www.cos.com 4 2026-05-21 2026-07-27 ok
accc-www.cos.com 6 2025-09-25 2026-07-29 ok
cicd-www.cos.com 4 2026-05-21 2026-07-27 ok
login.au.preprod-www.cos.com 1 2026-04-16 2026-04-16 nodata
stage-www.cos.com 6 2025-09-25 2026-07-29 ok
perf-www.cos.com 6 2025-09-25 2026-07-29 ok
lhci-www.cos.com 6 2026-04-26 2026-07-27 ok
qa-smockin-api-www.cos.com 6 2025-09-25 2026-07-29 ok
qa-smockin-www.cos.com 6 2025-09-25 2026-07-29 ok
accq-www.cos.com 6 2025-09-25 2026-07-29 ok
uat-www.cos.com 6 2025-09-25 2026-07-29 ok
login.au.uat-www.cos.com 2 2026-01-16 2026-06-10 ok
sit-www.cos.com 4 2026-05-21 2026-07-27 ok
login.au.sit-www.cos.com 2 2026-01-18 2026-06-11 ok
sytt-www.cos.com 4 2026-05-21 2026-07-27 ok
accv-www.cos.com 4 2026-05-21 2026-07-27 ok
dev-www.cos.com 10 2025-09-25 2026-08-25 ok
login.au.dev-www.cos.com 2 2026-01-22 2026-06-12 ok

Programmatic access, with DNS A records: API GET /v1/hosts/cos.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/cos.com.