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.

100 hosts (first page) · 462 ms

HostCertsFirst seenLast seenDNS
att.com 143 2025-07-02 2026-09-30 ok
*.att.com 10 2025-07-29 2026-09-29 —
voltage-pp-0000.att.com 5 2025-07-09 2026-06-26 ok
mcptest100.att.com 3 2026-08-25 2026-08-25 nodata
vaibhavtest100.att.com 10 2026-05-30 2026-09-12 nodata
mcptest200.att.com 1 2026-08-25 2026-08-25 nodata
mcptest300.att.com 3 2026-08-25 2026-08-25 nodata
egssmtp00.att.com 6 2025-12-29 2026-08-28 ok
dss-doamxww00.att.com 1 2025-11-17 2025-11-17 ok
gregTest-10.att.com 13 2026-05-27 2026-09-24 —
sig02010.att.com 1 2025-07-15 2025-07-15 nodata
mcptest110.att.com 3 2026-08-25 2026-08-25 nodata
mcptest210.att.com 3 2026-08-25 2026-08-25 nodata
mcptest310.att.com 3 2026-08-25 2026-08-25 nodata
afmfe10.att.com 4 2026-02-25 2026-08-18 ok
hvd-intl10.att.com 4 2026-06-02 2026-09-29 ok
test-cert-auto10.att.com 1 2025-09-25 2025-09-25 nodata
testvip10.att.com 1 2026-02-26 2026-02-26 nodata
gTest10.att.com 1 2026-05-08 2026-05-08 —
mcptest10.att.com 5 2026-08-25 2026-08-25 nodata
gregTest-20.att.com 3 2025-10-16 2026-09-15 —
mcptest120.att.com 3 2026-08-25 2026-08-25 nodata
mcptest220.att.com 3 2026-08-25 2026-08-25 nodata
mcptest320.att.com 1 2026-08-25 2026-08-25 nodata
testre420.att.com 2 2026-04-20 2026-04-20 nodata
afmfe20.att.com 4 2026-02-25 2026-08-18 ok
gTest20.att.com 1 2026-05-08 2026-05-08 —
mcptest20.att.com 6 2026-08-25 2026-08-25 nodata
testre1030.att.com 2 2025-10-30 2026-08-05 nodata
mcptest130.att.com 3 2026-08-25 2026-08-25 nodata
mcptest230.att.com 3 2026-08-25 2026-08-25 nodata
mcptest330.att.com 3 2026-08-25 2026-08-25 nodata
afmfe30.att.com 4 2026-02-25 2026-08-18 ok
gTest30.att.com 1 2026-05-08 2026-05-08 —
mcptest30.att.com 4 2026-08-25 2026-08-25 nodata
mcptest140.att.com 3 2026-08-25 2026-08-25 nodata
mcptest240.att.com 3 2026-08-25 2026-08-25 nodata
mcptest340.att.com 1 2026-08-25 2026-08-25 nodata
afmfe40.att.com 4 2026-02-25 2026-08-18 ok
gTest40.att.com 1 2026-05-08 2026-05-08 —
mcptest40.att.com 2 2026-08-25 2026-08-25 nodata
mcptest150.att.com 3 2026-08-25 2026-08-25 nodata
mcptest250.att.com 1 2026-08-25 2026-08-25 nodata
mcptest350.att.com 1 2026-08-25 2026-08-25 nodata
afmfe50.att.com 4 2026-02-25 2026-08-18 ok
gTest50.att.com 1 2026-05-08 2026-05-08 —
mcptest50.att.com 3 2026-08-25 2026-08-25 nodata
mcptest160.att.com 3 2026-08-25 2026-08-25 nodata
mcptest260.att.com 3 2026-08-25 2026-08-25 nodata
mcptest360.att.com 3 2026-08-25 2026-08-25 nodata
afmfe60.att.com 4 2026-02-25 2026-08-18 ok
gTest60.att.com 1 2026-05-08 2026-05-08 —
mcptest60.att.com 3 2026-08-25 2026-08-25 nodata
mcptest170.att.com 1 2026-08-25 2026-08-25 nodata
mcptest270.att.com 1 2026-08-25 2026-08-25 nodata
NCCDTL01JJ3570.att.com 1 2025-09-24 2025-09-24 —
afmfe70.att.com 4 2026-02-25 2026-08-18 ok
gTest70.att.com 1 2026-05-08 2026-05-08 —
mcptest70.att.com 1 2026-08-25 2026-08-25 nodata
mcptest180.att.com 3 2026-08-25 2026-08-25 nodata
mcptest280.att.com 3 2026-08-25 2026-08-25 nodata
afmfe80.att.com 4 2026-02-25 2026-08-18 ok
gTest80.att.com 1 2026-05-08 2026-05-08 —
mcptest80.att.com 3 2026-08-25 2026-08-25 nodata
mcptest190.att.com 3 2026-08-25 2026-08-25 nodata
mcptest290.att.com 3 2026-08-25 2026-08-25 nodata
ss4nj01tca01cmsw0.smst290.att.com 1 2026-06-05 2026-06-05 nodata
ss4nj01tca11cmsw0.smst290.att.com 1 2026-06-05 2026-06-05 nodata
ss4nj01tca02cmsw0.smst290.att.com 1 2026-06-05 2026-06-05 nodata
ss4nj01tca12cmsw0.smst290.att.com 1 2026-06-05 2026-06-05 nodata
ss4nj01tca04cmsw0.smst290.att.com 1 2026-06-05 2026-06-05 nodata
ss4nj01tca06cmsw0.smst290.att.com 1 2026-06-05 2026-06-05 nodata
mt4nj02bhnneam.smst290.att.com 1 2025-10-14 2025-10-14 nodata
ss4nj03bhsneam.smst290.att.com 6 2026-03-02 2026-08-22 nodata
mt4nj02bhxneam.smst290.att.com 4 2026-04-22 2026-09-26 nodata
afmfe90.att.com 4 2026-02-25 2026-08-18 ok
gTest90.att.com 1 2026-05-08 2026-05-08 —
mcptest90.att.com 3 2026-08-25 2026-08-25 nodata
df0000000bqaxma0.att.com 2 2026-02-23 2026-02-23 nodata
afmfe0.att.com 4 2026-02-25 2026-08-18 ok
gTest0.att.com 1 2026-05-08 2026-05-08 —
ado-21205-southcentralus-ariesogeo-prod-MOKS-vision-1.att.com 1 2026-03-29 2026-03-29 —
ado-21205-southcentralus-ariesogeo-prod-waba-vision-1.att.com 2 2026-03-30 2026-09-28 nodata
ado-21205-southcentralus-ariesogeo-prod-la-vision-1.att.com 1 2026-04-16 2026-04-16 nodata
ado-21205-southcentralus-ariesogeo-prod-epa-vision-1.att.com 1 2025-09-16 2025-09-16 nodata
ado-21205-southcentralus-ariesogeo-prod-ne-vision-1.att.com 1 2025-09-16 2025-09-16 nodata
ado-21205-southcentralus-ariesogeo-prod-miinoh-vision-1.att.com 1 2026-03-21 2026-03-21 nodata
ado-21205-southcentralus-ariesogeo-prod-ilwi-vision-1.att.com 2 2026-04-16 2026-04-16 nodata
ado-21205-southcentralus-ariesogeo-prod-nynj-vision-1.att.com 1 2025-09-16 2025-09-16 nodata
ado-21205-southcentralus-ariesogeo-prod-arok-vision-1.att.com 1 2026-03-25 2026-03-25 nodata
ado-21205-southcentralus-ariesogeo-prod-gs-vision-1.att.com 1 2026-04-16 2026-04-16 nodata
ado-21205-eastus2-ariesogeo-non-prod-test-dev-vision-1.att.com 4 2026-03-11 2026-09-09 nodata
ado-21205-southcentralus-ariesogeo-prod-ntx-vision-1.att.com 2 2026-03-30 2026-09-28 nodata
ado-21205-southcentralus-ariesogeo-prod-stx-vision-1.att.com 2 2026-03-30 2026-09-28 nodata
shm-us-east-1.att.com 2 2026-04-13 2026-04-13 nodata
sms-us-east-1.att.com 2 2025-07-17 2026-06-11 nodata
shm-test-us-east-1.att.com 2 2026-04-13 2026-04-13 nodata
gTest-1.att.com 1 2026-04-23 2026-04-23 —
ga484v-auto-test-1.att.com 1 2026-01-02 2026-01-02 nodata
ado-21205-eastus2-ariesogeo-non-prod-cas-test-1.att.com 1 2025-10-17 2025-10-17 nodata

Showing the first 100 hostnames — sign in with GitHub or Google to page the full list, or use the API with an API key: GET /v1/hosts/att.com.

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/att.com.