Southwest Airlines allows check-in starting 24 hours before departure via their website or mobile app. Checking in exactly at 24 hours is recommended because boarding positions are assigned based on check-in time due to their open seating policy. Early check-in improves chances of getting a better boarding position. Southwest offers EarlyBird Check-In, which automatically checks you in 36 hours before the flight and costs between $15 and $25 depending on flight length. EarlyBird is not available for Business Select fares, A-List members, parents traveling with children under six, unaccompanied minors, or passengers needing special assistance.

Passengers should arrive at the airport at least 2 hours before domestic flights and 3 hours before international flights to allow time for check-in, security, and unexpected delays. Southwest provides self-service kiosks to print boarding passes and baggage tags, curbside check-in for those with checked luggage, and staffed ticket counters for help with check-in or special needs. Boarding gates close 15 minutes before departure, and passengers must be at the gate with their boarding pass and checked bags ready for inspection.

To have a smooth travel experience with Southwest, check in at the 24-hour mark or use EarlyBird Check-In for earlier boarding. Arrive early at the airport to complete all procedures on time and avoid issues.