For a Southwest Airlines flight, it’s important to check in as early as possible to get the best possible boarding position, since Southwest does not assign seats in advance. Instead, boarding order is determined by check-in time, and passengers board in groups labeled A, B, or C, with numbers from 1 to 60. Check-in opens exactly 24 hours before the scheduled departure time of your flight, and the earlier you check in within that window, the better your spot in line will be. If you check in late, you may end up in the C group and be among the last to board, which could limit your seat choices and overhead bin space. You can check in online through the Southwest website, on the mobile app, or at the airport using a self-service kiosk or ticket counter. Many passengers set a reminder or alarm to check in exactly at the 24-hour mark. If you want to avoid the hassle of manual check-in, Southwest also offers EarlyBird Check-In, a paid service that automatically checks you in 36 hours before departure and typically results in a better boarding position. However, EarlyBird does not guarantee an A group boarding spot, but it usually provides a position ahead of most standard check-ins. For travelers who did not purchase EarlyBird, being prompt at the 24-hour mark is key. If you’re checking bags, Southwest recommends arriving at the airport at least two hours before your flight for domestic travel and three hours before for international flights. Baggage must be checked at least 45 minutes prior to departure, or you risk missing the flight. Check-in counters and kiosks at the airport usually open well in advance of the departure time, but for the best results, complete online check-in and simply drop off your bags. If you’re not checking luggage, you can head straight to security after checking in online and having your mobile or printed boarding pass ready. Travelers flying on a tight schedule or through busy airports should allow extra time for security screening, especially during holidays or peak hours. In summary, you should check in exactly 24 hours before your Southwest flight to get the best possible boarding position. If you want to avoid this step or get a better spot, consider buying EarlyBird Check-In. Arrive at the airport at least two hours before departure if you have checked baggage, and be aware of the 45-minute cut-off for checking bags. Even though seat selection happens on board, early check-in gives you more control over where you sit and your boarding experience. Planning ahead and being on time with check-in will help ensure a smoother, less stressful start to your trip with Southwest Airlines.