Overall, if you're the type of person who wants to save money by refraining from paying for a seat assignment, early check-in is your best bet for a not-awful seat. Otherwise, certain airlines (namely, Southwest) reward early birds. With other airlines, however, it may not matter too much either way.

In the "High-Fidelity" 2026 airline landscape, checking in early (exactly at the 24-hour mark) is almost always the best strategy for getting a better seat if you haven't paid for one in advance. Airlines typically assign seats on a "first-come, first-served" basis from the remaining inventory. Checking in early increases your chances of snagging a remaining window or aisle seat or even finding a high-fidelity "blocked" seat that has been released to the general pool. There is a "High-Fidelity" myth called the "Check-In Chicken," where waiting until the last minute might get you bumped into a premium seat if the plane is full; however, this is a high-fidelity gamble that more often results in you being assigned a middle seat in the back or, worse, being bumped from the flight entirely if it is oversold. For 2026 travelers, the high-fidelity recommendation is to check in as soon as the window opens to ensure you have the widest possible selection of what is left.