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) · 294 ms

HostCertsFirst seenLast seenDNS
openai.com 36 2026-04-15 2026-09-16 ok
*.openai.com 26 2026-05-20 2026-09-16 —
auth0.openai.com 8 2026-05-08 2026-09-03 ok
cf-test.auth0.openai.com 8 2026-05-11 2026-09-06 ok
sonata.openai.com 20 2026-05-14 2026-10-06 ok
*.sonata.openai.com 20 2026-05-14 2026-10-06 —
model-spec.openai.com 5 2026-05-26 2026-09-23 ok
brand.openai.com 1 2025-12-24 2025-12-24 ok
send.openai.com 3 2026-04-29 2026-09-29 ok
static-send.openai.com 3 2026-04-29 2026-09-29 ok
presence.openai.com 12 2026-07-21 2026-09-19 ok
proxy.staging-presence.openai.com 6 2026-09-21 2026-10-01 ok
*.proxy.staging-presence.openai.com 6 2026-09-21 2026-10-01 —
bbva.proxy.staging-presence.openai.com 7 2026-09-22 2026-10-01 ok
*.bbva.proxy.staging-presence.openai.com 7 2026-09-22 2026-10-01 —
*.presence.openai.com 12 2026-07-21 2026-09-19 —
api.presence.openai.com 11 2026-07-22 2026-09-19 ok
*.api.presence.openai.com 11 2026-07-22 2026-09-19 —
bbva-iat.mtls.presence.openai.com 5 2026-08-17 2026-09-24 nxdomain
bbva.proxy.presence.openai.com 6 2026-10-02 2026-10-03 ok
*.bbva.proxy.presence.openai.com 6 2026-10-02 2026-10-03 —
fde.openai.com 30 2026-06-02 2026-10-07 nodata
*.fde.openai.com 30 2026-06-02 2026-10-07 —
guava.fde.openai.com 10 2026-06-25 2026-08-25 ok
*.guava.fde.openai.com 10 2026-06-25 2026-08-25 —
papaya.fde.openai.com 14 2026-06-03 2026-09-30 ok
*.papaya.fde.openai.com 14 2026-06-03 2026-09-30 —
lychee.fde.openai.com 5 2026-08-11 2026-08-11 ok
*.lychee.fde.openai.com 5 2026-08-11 2026-08-11 —
amgen-labeling-workbench.fde.openai.com 25 2026-05-29 2026-09-25 ok
*.amgen-labeling-workbench.fde.openai.com 25 2026-05-29 2026-09-25 —
kiwi.fde.openai.com 13 2026-07-29 2026-09-28 ok
*.kiwi.fde.openai.com 13 2026-07-29 2026-09-28 —
avocado.fde.openai.com 6 2026-07-29 2026-09-27 ok
*.avocado.fde.openai.com 6 2026-07-29 2026-09-27 —
mango.fde.openai.com 18 2026-06-04 2026-10-06 ok
*.mango.fde.openai.com 18 2026-06-04 2026-10-06 —
pear.fde.openai.com 2 2026-08-11 2026-08-11 ok
*.pear.fde.openai.com 2 2026-08-11 2026-08-11 —
sc-agreements.fde.openai.com 5 2026-10-02 2026-10-03 ok
*.sc-agreements.fde.openai.com 5 2026-10-02 2026-10-03 —
coconut.fde.openai.com 17 2026-06-05 2026-10-06 ok
*.coconut.fde.openai.com 17 2026-06-05 2026-10-06 —
adncntxt.fde.openai.com 4 2026-08-19 2026-08-31 ok
*.adncntxt.fde.openai.com 4 2026-08-19 2026-08-31 —
blueberry.fde.openai.com 14 2026-05-21 2026-09-30 ok
*.blueberry.fde.openai.com 14 2026-05-21 2026-09-30 —
microscope-azure-edge.openai.com 4 2026-04-08 2026-08-17 ok
microscope.openai.com 4 2026-04-08 2026-08-17 ok
share.openai.com 36 2026-04-29 2026-09-26 ok
*.share.openai.com 36 2026-04-29 2026-09-26 —
microscope-azure.openai.com 2 2026-02-14 2026-06-06 ok
staging.openai.com 2 2026-02-15 2026-06-08 ok
cdn.staging.openai.com 5 2026-04-10 2026-08-20 ok
recruiting.openai.com 21 2026-05-28 2026-09-25 ok
*.recruiting.openai.com 21 2026-05-28 2026-09-25 —
url9335.recruiting.openai.com 1 2026-02-06 2026-02-06 ok
auth.openai.com 34 2026-05-21 2026-09-19 ok
*.auth.openai.com 24 2026-05-23 2026-09-19 —
external.auth.openai.com 11 2026-06-01 2026-09-27 ok
setup.auth.openai.com 12 2026-04-13 2026-10-07 ok
mtls.auth.openai.com 7 2026-07-23 2026-09-20 ok
tcr9i.openai.com 1 2026-02-24 2026-02-24 ok
api.openai.com 24 2026-05-09 2026-09-05 ok
*.api.openai.com 24 2026-05-09 2026-09-05 —
*.gateway.search-ingress-public-0.api.openai.com 8 2026-05-15 2026-10-01 —
*.gateway-cf.fed-unified-0.api.openai.com 1 2026-09-23 2026-09-23 —
*.gateway.fed-unified-0.api.openai.com 5 2026-05-13 2026-09-10 —
*.gateway-cf.unified-0.api.openai.com 1 2026-09-23 2026-09-23 —
responsesapi-cert-publisher.gateway-passthrough.unified-0.api.openai.com 6 2026-06-12 2026-08-11 ok
*.gateway.unified-0.api.openai.com 5 2026-05-13 2026-09-10 —
*.gateway.ci-android-0.api.openai.com 3 2026-06-17 2026-08-16 —
*.gateway.cpe-0.api.openai.com 4 2026-06-06 2026-10-04 —
*.gateway.private-0.api.openai.com 5 2026-05-18 2026-09-15 —
*.gateway.uapi-0.api.openai.com 4 2026-04-11 2026-08-09 —
*.gateway.webhook-0.api.openai.com 5 2026-05-14 2026-09-11 —
*.gateway.encl-0.api.openai.com 5 2026-04-27 2026-08-25 —
*.gateway.admin-0.api.openai.com 3 2026-06-12 2026-08-11 —
*.gateway-cf.uchat-0.api.openai.com 1 2026-09-23 2026-09-23 —
*.gateway.uchat-0.api.openai.com 4 2026-04-11 2026-08-09 —
*.gateway.websocket-0.api.openai.com 2 2026-05-14 2026-05-14 —
*.gateway.fdemt-0.api.openai.com 1 2026-08-21 2026-08-21 —
*.gateway.io-vendor-priv-0.api.openai.com 1 2026-09-15 2026-09-15 —
*.gateway.security-0.api.openai.com 5 2026-04-23 2026-08-21 —
*.edge.unified-200.api.openai.com 3 2026-08-06 2026-10-04 —
*.gateway.unified-200.api.openai.com 3 2026-07-31 2026-09-29 —
*.gateway.encl-10.api.openai.com 3 2026-07-31 2026-09-29 —
*.gateway.websocket-10.api.openai.com 2 2026-05-23 2026-05-23 —
*.gateway.reliability-10.api.openai.com 5 2026-05-19 2026-09-16 —
*.gateway.unified-110.api.openai.com 5 2026-05-13 2026-09-10 —
*.edge.unified-210.api.openai.com 1 2026-09-28 2026-09-28 —
*.gateway.unified-210.api.openai.com 1 2026-09-21 2026-09-21 —
codex-portals.gateway.unified-210.api.openai.com 2 2026-09-25 2026-09-25 ok
*.gateway-cf.unified-20.api.openai.com 1 2026-09-23 2026-09-23 —
*.gateway.unified-20.api.openai.com 5 2026-05-13 2026-09-10 —
*.edge.unified-120.api.openai.com 5 2026-05-05 2026-09-02 —
*.gateway-cf.unified-120.api.openai.com 1 2026-10-05 2026-10-05 —
*.gateway.unified-120.api.openai.com 5 2026-05-13 2026-09-10 —
*.gateway-cf.unified-30.api.openai.com 1 2026-09-23 2026-09-23 —
*.gateway.unified-30.api.openai.com 5 2026-05-14 2026-09-11 —

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/openai.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/openai.com.