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) · 392 ms

HostCertsFirst seenLast seenDNS
principal.com 14 2025-07-23 2026-09-29 ok
ul6020.principal.com 2 2025-07-17 2026-06-17 nxdomain
ul4940.principal.com 2 2025-08-28 2026-07-23 nxdomain
secure09.user0.principal.com 1 2025-12-04 2025-12-04 ok
inside.user0.principal.com 2 2025-08-11 2026-07-13 nxdomain
secure09.unit0.principal.com 1 2025-12-04 2025-12-04 nxdomain
inside.unit0.principal.com 2 2025-08-11 2026-07-13 nxdomain
testexternal2026-1.principal.com 3 2026-02-11 2026-02-18 nxdomain
pgidsmjob014t-1.principal.com 1 2025-09-12 2025-09-12 nxdomain
okta-sandbox-1.principal.com 9 2026-05-05 2026-10-07 ok
challenge.okta-sandbox-1.principal.com 1 2025-06-20 2025-06-20 nxdomain
ws101.principal.com 3 2026-01-06 2026-09-23 nxdomain
PFGDSMCONNDRT01.principal.com 2 2026-09-16 2026-09-16 —
secure01.principal.com 1 2026-06-08 2026-06-08 ok
pfgdsmisegnp01.principal.com 2 2025-09-30 2026-07-31 nxdomain
mft01.principal.com 2 2025-08-28 2026-07-23 ok
mftInt01.principal.com 2 2025-08-28 2026-07-23 —
CHISBC11.principal.com 2 2025-07-29 2026-07-24 —
DSMSBC11.principal.com 2 2025-07-29 2026-07-24 —
ul6021.principal.com 2 2025-07-17 2026-06-17 nxdomain
ul7131.principal.com 2 2025-07-21 2026-06-16 nxdomain
ul4941.principal.com 2 2025-08-28 2026-07-23 nxdomain
ul5191.principal.com 2 2025-07-17 2026-06-17 nxdomain
vault-use1.principal.com 2 2025-09-05 2026-08-27 ok
nonprodvault-use1.principal.com 2 2025-09-05 2026-08-25 ok
vault-encrypt-use1.principal.com 2 2025-08-05 2026-07-31 ok
oag1.principal.com 3 2025-07-24 2026-07-16 nxdomain
secure09.user1.principal.com 1 2025-12-04 2025-12-04 ok
inside.user1.principal.com 2 2025-08-11 2026-07-13 nxdomain
secure09.unit1.principal.com 1 2025-12-04 2025-12-04 nxdomain
inside.unit1.principal.com 2 2025-08-11 2026-07-13 nxdomain
mx1.principal.com 2 2025-10-23 2026-09-29 ok
rmx1.principal.com 3 2025-07-23 2026-07-14 ok
testexternal2026-2.principal.com 1 2026-02-23 2026-02-23 nxdomain
okta-sandbox-2.principal.com 9 2026-05-04 2026-10-06 ok
ws102.principal.com 1 2026-04-27 2026-04-27 nxdomain
secure02.principal.com 2 2025-08-20 2026-07-21 ok
pfgdsmisegnp02.principal.com 2 2025-09-30 2026-07-31 nxdomain
mft02.principal.com 2 2025-08-28 2026-07-23 ok
mftInt02.principal.com 2 2025-08-28 2026-07-23 —
ul7132.principal.com 2 2025-08-04 2026-07-10 nxdomain
ul3982.principal.com 2 2025-08-28 2026-07-23 nxdomain
ul5192.principal.com 2 2025-07-17 2026-06-17 nxdomain
oag2.principal.com 3 2025-07-24 2026-07-16 nxdomain
hkg.smtp2.principal.com 3 2025-07-17 2026-07-09 nxdomain
scl.smtp2.principal.com 3 2025-07-17 2026-07-09 nxdomain
mty.smtp2.principal.com 3 2025-07-17 2026-07-09 nxdomain
secure09.user2.principal.com 1 2025-12-04 2025-12-04 ok
inside.user2.principal.com 2 2025-08-11 2026-07-13 nxdomain
secure09.unit2.principal.com 1 2025-12-04 2025-12-04 nxdomain
inside.unit2.principal.com 2 2025-08-11 2026-07-13 nxdomain
virtualworkspace-v2.principal.com 1 2025-11-28 2025-11-28 ok
vault-encrypt-usw2.principal.com 1 2026-05-08 2026-05-08 nxdomain
mx2.principal.com 2 2025-10-23 2026-09-29 ok
rmx2.principal.com 3 2025-07-23 2026-07-14 ok
tmx2.principal.com 6 2025-09-02 2026-09-29 ok
ws103.principal.com 3 2026-01-08 2026-09-24 nxdomain
ul7133.principal.com 2 2025-08-04 2026-07-10 nxdomain
ul4943.principal.com 2 2025-07-21 2026-06-16 nxdomain
ul3053.principal.com 1 2025-12-08 2025-12-08 nxdomain
ul3983.principal.com 2 2025-08-28 2026-07-23 nxdomain
ul5193.principal.com 2 2025-07-17 2026-06-17 nxdomain
ul11793.principal.com 2 2025-07-24 2026-07-15 nxdomain
POP3.principal.com 3 2025-07-17 2026-07-09 —
oag3.principal.com 3 2025-07-24 2026-07-16 nxdomain
secure09.user3.principal.com 1 2025-12-04 2025-12-04 ok
inside.user3.principal.com 2 2025-08-11 2026-07-13 nxdomain
secure09.unit3.principal.com 1 2025-12-04 2025-12-04 nxdomain
inside.unit3.principal.com 2 2025-08-11 2026-07-13 nxdomain
secureprint3.principal.com 2 2025-12-04 2025-12-16 ok
mx3.principal.com 2 2025-10-23 2026-09-29 ok
ul6014.principal.com 2 2025-07-17 2026-06-17 nxdomain
ul7134.principal.com 2 2025-08-28 2026-07-23 nxdomain
ul7144.principal.com 2 2025-07-21 2026-06-16 nxdomain
ul4944.principal.com 2 2025-08-04 2026-07-10 nxdomain
ul5194.principal.com 2 2025-07-17 2026-06-17 nxdomain
ul2694.principal.com 1 2025-12-08 2025-12-08 nxdomain
ul11794.principal.com 2 2025-08-18 2026-08-06 nxdomain
IMAP4.principal.com 3 2025-07-17 2026-07-09 —
oag4.principal.com 3 2025-07-24 2026-07-16 nxdomain
secure09.user4.principal.com 1 2025-12-04 2025-12-04 ok
inside.user4.principal.com 2 2025-08-11 2026-07-13 nxdomain
secure09.unit4.principal.com 1 2025-12-04 2025-12-04 nxdomain
inside.unit4.principal.com 2 2025-08-11 2026-07-13 nxdomain
secure05.principal.com 4 2025-10-13 2026-09-14 ok
pacificlife.secure05.principal.com 4 2026-03-31 2026-09-16 ok
admin.secure05.principal.com 3 2026-03-09 2026-08-25 nxdomain
ul6015.principal.com 2 2025-07-17 2026-06-17 nxdomain
testexternal2025.principal.com 2 2025-10-14 2025-11-19 nxdomain
ul3135.principal.com 1 2026-07-13 2026-07-13 nxdomain
ul7135.principal.com 2 2025-08-28 2026-07-23 nxdomain
ul7145.principal.com 2 2025-08-04 2026-07-10 nxdomain
ul4945.principal.com 2 2025-08-04 2026-07-10 nxdomain
ul5195.principal.com 2 2025-07-17 2026-06-17 nxdomain
ul11795.principal.com 2 2025-08-11 2026-07-15 nxdomain
oag5.principal.com 3 2025-07-24 2026-07-16 nxdomain
secure09.user5.principal.com 1 2025-12-04 2025-12-04 ok
inside.user5.principal.com 2 2025-08-11 2026-07-13 nxdomain
secure09.unit5.principal.com 1 2025-12-04 2025-12-04 nxdomain
inside.unit5.principal.com 2 2025-08-11 2026-07-13 nxdomain

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/principal.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/principal.com.