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) · 308 ms

HostCertsFirst seenLast seenDNS
guard.io 4 2026-04-24 2026-09-30 ok
lp-h-1120.guard.io 5 2026-05-19 2026-09-21 ok
lp-security-app-31.guard.io 5 2026-05-29 2026-09-29 ok
lp-h-2271.guard.io 5 2026-05-15 2026-09-16 ok
lp1.guard.io 5 2026-05-06 2026-09-08 ok
lp-lp803-92.guard.io 5 2026-05-21 2026-09-24 ok
lp-whimsical-welcome-test-j8asd2.guard.io 5 2026-04-26 2026-08-27 ok
lp-youtube2.guard.io 5 2026-04-22 2026-08-26 ok
cdn2.guard.io 3 2026-05-18 2026-09-03 ok
lp2.guard.io 5 2026-05-04 2026-09-04 ok
lp-lp803.guard.io 5 2026-05-18 2026-09-20 ok
lp3.guard.io 5 2026-05-05 2026-09-04 ok
lp4.guard.io 5 2026-05-08 2026-09-08 ok
lp-lp803-59.guard.io 5 2026-05-20 2026-09-21 ok
lp-ya.guard.io 5 2026-04-29 2026-08-30 ok
lp-social-lp-ya.guard.io 3 2026-06-10 2026-08-12 ok
mob.guard.io 7 2026-04-10 2026-09-30 ok
lp-pc.guard.io 5 2026-04-27 2026-08-31 ok
lp-cozyshield.guard.io 5 2026-06-02 2026-10-02 ok
goalie.guard.io 2 2026-09-30 2026-09-30 ok
me.guard.io 5 2026-04-28 2026-08-30 ok
iframe.guard.io 5 2026-05-13 2026-09-29 ok
site.guard.io 10 2026-04-13 2026-08-10 ok
sniff.guard.io 6 2026-06-01 2026-10-02 ok
*.testing.guard.io 1194 2026-04-09 2026-10-06 —
*.vip-135-upsell-19110.testing.guard.io 18 2026-05-14 2026-05-17 —
*.grow-1148-phase-18310.testing.guard.io 2 2026-04-14 2026-04-14 —
*.claude-partial-auth-22510.testing.guard.io 1 2026-08-25 2026-08-25 —
*.claude-upbeat-payne-19810.testing.guard.io 46 2026-05-28 2026-06-07 —
*.cor-338-enable-18020.testing.guard.io 7 2026-04-09 2026-04-12 —
*.pay-493-amazon-22430.testing.guard.io 37 2026-08-17 2026-08-25 —
*.pay-967-deferred-22730.testing.guard.io 46 2026-08-31 2026-09-15 —
*.pay-796-bluesnap-21540.testing.guard.io 76 2026-07-20 2026-07-28 —
*.c-refactor-fraud-18540.testing.guard.io 2 2026-04-26 2026-04-26 —
*.c-fix-audit-18740.testing.guard.io 32 2026-04-30 2026-05-03 —
*.grow-1382-animated-18840.testing.guard.io 2 2026-04-30 2026-04-30 —
*.claude-dreamy-visvesvaraya-19840.testing.guard.io 711 2026-05-31 2026-10-06 —
*.pay-1044-debit-22940.testing.guard.io 6 2026-09-08 2026-09-10 —
*.pay-350-redo2-19150.testing.guard.io 52 2026-05-10 2026-05-11 —
*.grow-2325-migrate-23250.testing.guard.io 4 2026-09-15 2026-09-16 —
*.worktree-snug-wibbling-19250.testing.guard.io 4 2026-05-12 2026-05-12 —
*.worktree-pay-790-21550.testing.guard.io 20 2026-07-20 2026-07-22 —
*.pay-578-taxes-19650.testing.guard.io 72 2026-05-26 2026-06-09 —
*.pay-849-save-21950.testing.guard.io 170 2026-08-02 2026-08-31 —
*.feat-pay-1175-23950.testing.guard.io 17 2026-10-01 2026-10-06 —
*.grow-1708-email-20260.testing.guard.io 34 2026-06-11 2026-06-21 —
*.prt-1944-post-19360.testing.guard.io 807 2026-05-14 2026-10-06 —
*.se-259-zendesk-21960.testing.guard.io 301 2026-08-02 2026-10-06 —
*.grow-2416-quiz-24270.testing.guard.io 1 2026-10-06 2026-10-06 —
*.grow-1816-breach-20470.testing.guard.io 633 2026-06-19 2026-10-06 —
*.pay-558-store-19180.testing.guard.io 132 2026-05-11 2026-05-20 —
*.fix-serve-meta-20390.testing.guard.io 2 2026-06-16 2026-06-16 —
*.vip-239-upsell-20690.testing.guard.io 595 2026-06-25 2026-10-06 —
*.pay-1041-testing-22790.testing.guard.io 2 2026-09-01 2026-09-01 —
*.pay-916-feat-22201.testing.guard.io 15 2026-08-09 2026-08-11 —
*.pay-3ds-adyen-22801.testing.guard.io 2 2026-09-01 2026-09-01 —
*.eng-1348-mmap-21901.testing.guard.io 4 2026-07-30 2026-07-30 —
*.grow-1226-force-19011.testing.guard.io 1015 2026-05-05 2026-10-06 —
*.pay-471-refactorfront-18911.testing.guard.io 44 2026-05-04 2026-05-07 —
*.fix-activation-value-18521.testing.guard.io 1 2026-04-21 2026-04-21 —
*.pay-823-add-21621.testing.guard.io 70 2026-07-21 2026-07-30 —
*.worktree-pay-1150-23721.testing.guard.io 5 2026-09-28 2026-09-28 —
*.worktree-grow-1226-19031.testing.guard.io 999 2026-05-06 2026-10-06 —
*.pay-565-feat-21731.testing.guard.io 68 2026-07-25 2026-08-10 —
*.worktree-wondrous-questing-19731.testing.guard.io 16 2026-05-27 2026-05-28 —
*.set-83-set-19041.testing.guard.io 84 2026-05-18 2026-05-25 —
*.pay-803-block-21241.testing.guard.io 54 2026-07-12 2026-07-15 —
*.grow-1730-charges-20441.testing.guard.io 639 2026-06-16 2026-10-06 —
*.vip-135-rerun-19441.testing.guard.io 2 2026-05-18 2026-05-18 —
*.fix-front-update-20051.testing.guard.io 683 2026-06-04 2026-10-06 —
*.pay-605-accounting-20551.testing.guard.io 168 2026-06-23 2026-07-15 —
*.set-265-resume-20851.testing.guard.io 2 2026-06-29 2026-06-29 —
*.pay-959-apply-22561.testing.guard.io 93 2026-08-25 2026-09-16 —
*.grow-2229-web-22761.testing.guard.io 2 2026-09-01 2026-09-01 —
*.worktree-lcy-36-17961.testing.guard.io 32 2026-04-14 2026-05-03 —
*.pay-687-unify-21171.testing.guard.io 76 2026-07-08 2026-07-15 —
*.pay-602-track-20771.testing.guard.io 6 2026-06-29 2026-06-29 —
*.feat-eng-649-18781.testing.guard.io 386 2026-04-29 2026-06-01 —
*.pay-886-fix-22091.testing.guard.io 57 2026-08-10 2026-08-23 —
*.sqd-97-existing-18491.testing.guard.io 1 2026-04-20 2026-04-20 —
*.c-update-customerio-18691.testing.guard.io 6 2026-04-28 2026-04-28 —
*.second-iteration-grow-19791.testing.guard.io 12 2026-05-28 2026-06-01 —
*.grow-1870-forter-20891.testing.guard.io 6 2026-07-01 2026-07-02 —
*.worktree-pay-1188-24202.testing.guard.io 8 2026-10-05 2026-10-06 —
*.grow-1084-pspm-17802.testing.guard.io 7 2026-04-09 2026-04-12 —
*.se-400-plan-23312.testing.guard.io 74 2026-09-16 2026-10-06 —
*.feat-pay-851-22512.testing.guard.io 14 2026-08-19 2026-08-24 —
*.se-235-tier-21612.testing.guard.io 383 2026-07-21 2026-10-06 —
*.pr-19110-test-19222.testing.guard.io 825 2026-05-18 2026-10-06 —
*.pay-475-downgrade-19132.testing.guard.io 20 2026-05-10 2026-05-10 —
*.feat-pay-298-23232.testing.guard.io 56 2026-09-15 2026-09-30 —
*.infra-795-gcs-21732.testing.guard.io 27 2026-08-04 2026-08-10 —
*.fix-pay-1003-23732.testing.guard.io 9 2026-09-28 2026-09-29 —
*.upgrade-google-ads-20832.testing.guard.io 4 2026-06-29 2026-06-29 —
*.pay-451-pay-20242.testing.guard.io 22 2026-06-14 2026-06-16 —
*.lcy-618-security-19242.testing.guard.io 10 2026-05-12 2026-05-13 —
*.test-env-bootstrap-19442.testing.guard.io 813 2026-05-18 2026-10-06 —
*.infra-621-gunicorn-18542.testing.guard.io 10 2026-04-28 2026-04-29 —
*.pay-591-upgrade-19842.testing.guard.io 80 2026-05-31 2026-06-19 —
*.se-207-charges-21252.testing.guard.io 52 2026-07-14 2026-07-19 —

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/guard.io.

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/guard.io.