What is EarlyBird Check-In? It’s a convenient and time-saving service offered by Southwest Airlines that allows you to automatically check in for your flight before the standard check-in window opens. With EarlyBird Check-In, you’re assigned a boarding position ahead of those who check in during the traditional 24-hour window, giving you a better chance to secure your preferred seat and board the plane earlier. This service is especially beneficial for travelers who want to avoid the stress of remembering to check in exactly 24 hours before departure or those who prefer to have more seating options, such as aisle or window seats.