How Early Should I Check In for a Southwest Flight? A Complete Guide

If you’re flying with Southwest Airlines, one of the most important steps in your travel day is knowing how early you should check in. Unlike many other major U.S. airlines, Southwest does not assign seat numbers—instead, it uses an open seating policy based on a boarding group and position. That means the earlier you check in, the better your spot in line and the better your chances of getting your preferred seat. So, how early should you check in for a Southwest flight? The short answer: as close to 24 hours before departure as possible.

Southwest opens online check-in exactly 24 hours before your flight’s scheduled departure time. This is your opportunity to secure a good boarding position (A, B, or C group). The boarding groups are assigned on a first-come, first-served basis. If you wait too long after the 24-hour mark to check in, you may end up in a later group with fewer seating options, especially if the flight is full. So, for the best seats—especially if you're traveling with family or want a window or aisle—log in and check in online right at the 24-hour mark.

You can check in through the Southwest Airlines website or by using the Southwest mobile app, both of which allow you to check in and get a mobile boarding pass. You can also print your boarding pass or send it to your email. If you have the app, you’ll get a notification when it’s time to check in, making it easier not to miss that key window.

If you're unable to check in right at 24 hours, you can also purchase EarlyBird Check-In®, which automatically checks you in 36 hours before your flight—giving you an earlier boarding position than most other passengers. This service is especially helpful for those who don’t want to worry about checking in manually or may not have internet access at the 24-hour mark.

In terms of airport arrival time, Southwest recommends that travelers arrive at the airport at least two hours before domestic flights and three hours before international flights, especially if you need to check bags, go through security, or are traveling during busy periods. Southwest’s bag check counters usually close 45 minutes before domestic flights and 60 minutes before international flights, so be sure to check your luggage well before those cutoff times.

In summary, you should check in online exactly 24 hours before departure to get the best possible boarding position. If convenience matters more than timing, consider EarlyBird Check-In®. And on the day of travel, plan to be at the airport at least two hours early for domestic flights to allow enough time for bag check, security, and boarding. With these tips in mind, you’ll be well-prepared for a smooth and stress-free experience flying with Southwest Airlines.