Wondering how to check in Spirit Airlines flights? It’s quick and convenient. You can check in online via the Spirit Airlines website or mobile app starting 24 hours before your flight and up to one hour prior to departure. This option lets you choose seats, add bags, and get a mobile or printable boarding pass. Online check-in is free and the fastest way to prepare for your flight. If needed, you can also check in at airport kiosks or ticket counters, but extra fees may apply for printed boarding passes or personal assistance. To save time and money, it’s best to check in online and arrive early at the airport.