Check in online is always better than waiting until the airport, as it is the quickest way to print your boarding pass and seal through the airport confidently. According to
[u]Spirit airlines the best time to check in online[/u] is 24 hours before your flight and it ends 1 hour before departure. You can check in physically at Spirit Airlines' airport counter from 3 hours to 45 minutes prior to departure for domestic flights and from 3 hours to 60 minutes prior to departure for international flights.
