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) · 432 ms

HostCertsFirst seenLast seenDNS
southwest.com 12 2025-07-18 2026-09-15 ok
api-mobile-misc.dev10.southwest.com 2 2025-08-05 2026-06-24 ok
api-air-misc.dev10.southwest.com 2 2025-07-28 2026-06-23 ok
www.api-air-misc.dev10.southwest.com 2 2025-07-28 2026-06-23 nxdomain
alice.dev10.southwest.com 2 2026-02-01 2026-02-18 ok
api-alice.dev10.southwest.com 2 2026-03-30 2026-08-12 ok
api-landing-page.dev10.southwest.com 2 2025-07-28 2026-06-24 ok
api-nonrev-landing-page.dev10.southwest.com 2 2025-08-05 2026-06-24 ok
api-air-change.dev10.southwest.com 2 2025-07-28 2026-06-24 ok
www.api-air-change.dev10.southwest.com 2 2025-07-28 2026-06-24 nxdomain
mobile.dev10.southwest.com 2 2026-02-01 2026-02-18 ok
api-chase.dev10.southwest.com 2 2025-08-05 2026-06-23 ok
www.api-chase.dev10.southwest.com 2 2025-08-05 2026-06-23 nxdomain
api-logging.dev10.southwest.com 2 2025-07-30 2026-06-23 ok
api-mobile-air-booking.dev10.southwest.com 2 2025-07-29 2026-06-24 ok
api-air-booking.dev10.southwest.com 2 2025-07-28 2026-06-23 ok
www.api-air-booking.dev10.southwest.com 2 2025-07-28 2026-06-23 nxdomain
api-nonrev-air-booking.dev10.southwest.com 2 2025-08-05 2026-06-24 ok
api-mobile-air-shopping.dev10.southwest.com 2 2025-08-05 2026-06-24 ok
api-hotel.dev10.southwest.com 2 2025-07-28 2026-06-24 ok
api-air-checkin.dev10.southwest.com 2 2025-07-28 2026-06-23 ok
www.api-air-checkin.dev10.southwest.com 2 2025-07-28 2026-06-23 nxdomain
api-corporate-admin.dev10.southwest.com 2 2025-07-28 2026-06-24 ok
api-air-manage-reservation.dev10.southwest.com 2 2025-07-27 2026-06-23 ok
api-car.dev10.southwest.com 2 2025-07-30 2026-06-23 ok
www.api-car.dev10.southwest.com 2 2025-07-30 2026-06-23 nxdomain
api-chase-dao-simulator.dev10.southwest.com 1 2025-12-26 2025-12-26 ok
api-travel-funds.dev10.southwest.com 1 2025-12-26 2025-12-26 ok
chris.dev10.southwest.com 2 2026-02-01 2026-02-18 ok
api-chris.dev10.southwest.com 2 2026-03-30 2026-08-12 ok
chase-tools.dev10.southwest.com 2 2026-02-01 2026-02-18 ok
api-mobile-air-operations.dev10.southwest.com 2 2025-07-30 2026-06-24 ok
api-air-operations.dev10.southwest.com 2 2025-07-30 2026-06-23 ok
www.api-air-operations.dev10.southwest.com 2 2025-07-30 2026-06-23 nxdomain
api-car-reservations.dev10.southwest.com 2 2025-07-28 2026-06-23 nxdomain
www.api-car-reservations.dev10.southwest.com 2 2025-07-28 2026-06-23 nxdomain
api-mobile-travel-requirements.dev10.southwest.com 1 2026-02-24 2026-02-24 ok
api-travel-requirements.dev10.southwest.com 1 2026-02-24 2026-02-24 ok
api-discounts.dev10.southwest.com 2 2025-07-28 2026-06-24 ok
api-baggage-management.dev10.southwest.com 1 2026-02-08 2026-02-08 ok
api-upgraded-boarding-management.dev10.southwest.com 2 2025-07-29 2026-06-24 ok
api-ancillary-management.dev10.southwest.com 2 2025-07-28 2026-06-24 ok
api-loyalty-management.dev10.southwest.com 2 2025-08-05 2026-06-24 ok
southwest.dev10.southwest.com 4 2025-07-27 2026-06-23 ok
espanol-southwest.dev10.southwest.com 4 2025-11-18 2026-09-13 ok
www.southwest.dev10.southwest.com 2 2025-07-27 2026-06-23 nxdomain
nonrev.dev10.southwest.com 2 2026-02-01 2026-02-18 ok
api-content-delivery.dev10.southwest.com 2 2025-07-30 2026-06-23 ok
www.api-content-delivery.dev10.southwest.com 2 2025-07-30 2026-06-23 nxdomain
api-security.dev10.southwest.com 2 2025-07-28 2026-06-23 ok
swabiz.dev10.southwest.com 3 2025-08-01 2026-02-18 ok
espanol-swabiz.dev10.southwest.com 4 2025-11-18 2026-09-13 ok
webfids.qa1.w11.southwest.com 2 2026-02-24 2026-02-24 ok
webfids.qa2.w11.southwest.com 2 2026-02-24 2026-02-24 ok
webfids.prod.w11.southwest.com 2 2025-09-26 2026-08-25 ok
alice.w11.southwest.com 2 2025-08-04 2025-09-26 nxdomain
chris.w11.southwest.com 2 2025-08-04 2025-09-26 nxdomain
webfids.prod.w21.southwest.com 2 2025-09-26 2026-08-25 ok
alice.w21.southwest.com 1 2025-09-26 2025-09-26 nxdomain
chris.w21.southwest.com 1 2025-09-26 2025-09-26 nxdomain
api-mobile-misc.qa1.southwest.com 2 2026-04-06 2026-08-21 ok
api-air-misc.qa1.southwest.com 2 2026-04-07 2026-08-21 ok
alice.qa1.southwest.com 5 2025-07-20 2026-02-20 ok
api-alice.qa1.southwest.com 2 2025-07-22 2026-06-18 ok
api-landing-page.qa1.southwest.com 2 2026-04-07 2026-08-21 ok
api-nonrev-landing-page.qa1.southwest.com 2 2025-07-22 2026-06-18 ok
api-air-change.qa1.southwest.com 2 2026-04-07 2026-08-21 ok
mobile.qa1.southwest.com 4 2026-01-26 2026-02-20 ok
mobile-offline.qa1.southwest.com 4 2026-01-26 2026-02-20 ok
api-chase.qa1.southwest.com 2 2025-07-22 2026-06-18 ok
api-logging.qa1.southwest.com 1 2026-04-06 2026-04-06 ok
www.api-logging.qa1.southwest.com 1 2026-04-06 2026-04-06 nxdomain
api-mobile-air-booking.qa1.southwest.com 2 2026-04-07 2026-08-21 ok
api-air-booking.qa1.southwest.com 2 2026-03-31 2026-08-20 ok
api-nonrev-air-booking.qa1.southwest.com 2 2025-07-22 2026-06-18 ok
api-mobile-air-shopping.qa1.southwest.com 2 2025-07-22 2026-06-18 ok
travel-api.qa1.southwest.com 1 2026-04-06 2026-04-06 ok
www.travel-api.qa1.southwest.com 1 2026-04-06 2026-04-06 nxdomain
api-travel.qa1.southwest.com 1 2026-03-31 2026-03-31 ok
www.api-travel.qa1.southwest.com 1 2026-03-31 2026-03-31 nxdomain
api-air-checkin.qa1.southwest.com 2 2026-04-07 2026-08-21 ok
api-corporate-admin.qa1.southwest.com 3 2026-04-06 2026-08-21 ok
api-air-manage-reservation.qa1.southwest.com 2 2025-08-07 2026-07-06 ok
api-car.qa1.southwest.com 2 2026-04-06 2026-08-21 ok
api-chase-simulator.qa1.southwest.com 2 2025-08-07 2026-07-06 ok
www.api-chase-simulator.qa1.southwest.com 2 2025-08-07 2026-07-06 nxdomain
api-chase-dao-simulator.qa1.southwest.com 2 2025-12-26 2026-07-06 ok
api-travel-funds.qa1.southwest.com 1 2025-12-26 2025-12-26 ok
chris.qa1.southwest.com 5 2025-07-20 2026-02-20 ok
api-chris.qa1.southwest.com 2 2025-07-20 2026-06-18 ok
chase-tools.qa1.southwest.com 4 2026-01-26 2026-02-20 ok
api-mobile-air-operations.qa1.southwest.com 2 2026-04-07 2026-08-21 ok
api-air-operations.qa1.southwest.com 2 2026-03-31 2026-08-20 ok
www.api-air-operations.qa1.southwest.com 2 2026-03-31 2026-08-20 nxdomain
api-car-reservations.qa1.southwest.com 2 2026-03-31 2026-08-20 ok
www.api-car-reservations.qa1.southwest.com 2 2026-03-31 2026-08-20 nxdomain
api-mobile-travel-requirements.qa1.southwest.com 2 2025-08-20 2026-07-06 ok
api-travel-requirements.qa1.southwest.com 2 2025-08-20 2026-07-06 nxdomain
api-baggage-management.qa1.southwest.com 2 2026-03-30 2026-08-20 ok
api-upgraded-boarding-management.qa1.southwest.com 2 2025-08-07 2026-07-06 ok

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/southwest.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/southwest.com.