Frontier Airlines allows passengers to check in online starting 24 hours before departure until 60 minutes prior to the flight. You can check in on their website by entering your reservation details or via the Frontier mobile app, which also provides boarding passes and flight updates. After online check-in, if you only have carry-on luggage, you can proceed directly to security and your gate. However, if you have checked baggage, you must drop it off at the airport counter at least 60 minutes before departure. Missing the check-in or boarding time may lead to ticket cancellation, including any connecting flights.

Frontier also offers self-service kiosks at select airports where you can check in, print boarding passes, and tag checked bags. These kiosks open about 45 minutes before domestic flights and 60 minutes before international flights. For passengers who prefer in-person assistance, airport counters open two hours before departure and close 45 minutes before domestic flights and 60 minutes before international flights. Counter check-in may involve extra fees.

It is recommended to arrive at the airport at least two hours before domestic flights and three hours before international flights to allow sufficient time for check-in, security, and boarding. Passengers with special needs, unaccompanied minors, or traveling with pets should contact Frontier Airlines in advance to arrange assistance.

In summary, Frontier Airlines provides multiple check-in methods: online, mobile app, self-service kiosks, and airport counters. Passengers should complete check-in within the allowed timeframes and arrive early at the airport to ensure a smooth travel experience.