Does It Matter What Time You Check in for a Flight?

Given the fact that many airlines — especially low-cost airlines — charge for seat selection, it’s tempting to skip that add-on if you’re traveling on a budget or if you’re flying solo. But if you do opt to select your seat in advance, either for free or for a fee, you may be wondering if it really matters what time you check in for a flight. And if you’re checking bags, why waste time checking in online when you have to visit the counter at the airport anyway? However, the 24-hour window to check in online before your departure does matter for a number of reasons — here’s why you shouldn’t wait to do it until you get to the airport. 

You Often Get Better Seats

It’s always better to have options: If you didn’t pay to select a seat ahead of time, checking in to your flight early will ensure that you can choose between a window or an aisle seat before the rest of the seats on the plane are assigned. If other passengers beat you to the punch, chances are that you’ll end up with the dreaded middle seat and be unable to pay for an alternative or request a swap — especially if you have limited mobility and need to easily get in and out of your row, or if you wish to be seated closer to the bathroom. Selecting your seat ahead of time when you purchase your flight is a surefire way to avoid a headache, but if you opt to wait until check-in opens, make sure you grab your boarding pass right away. 

You May Have Upgrade Opportunities 

Some airlines allow you to secure paid upgrades at check-in, so if there are only one or two upgrades available, the early bird will get the worm. These upgrade offers are often a great deal, particularly if the airline wants to fill unsold seats in the front cabin. Additionally, many airlines will upgrade frequent flyers who hold elite status in the days leading up to departure, which may free up better seats in the back of the plane. Likewise, some economy-class seats may be blocked for operational reasons or sold for an extra fee, but if they remain empty or unsold, they could become available to select for free come check-in time. Again, the early bird gets the worm, so it’s always worth checking the seat map as soon as check-in opens to see if your options have changed.

You Could Board the Plane Faster

On some airlines, boarding order is determined by check-in time, so being among the first to check in means you can get situated on the plane before other passengers. For example, on Southwest Airlines, those who receive a boarding number that starts with A, based on check-in time, will also get to pick their own seats first, beating out those in B or C groups. Checking in early online will ensure a better boarding zone, so you don’t have to be the last on the plane. Boarding earlier can also help you secure overhead bin space for your carry-on. Note, however, that Southwest is changing its policy in 2026.

You Can Avoid Check-In Lines at the Counter

Although it’s generally recommended to arrive at the airport two hours before domestic flights and three hours before international flights, many passengers often mismanage time and end up in long counter lines. This can be especially true if they didn’t check in online and still need a seat or to purchase carry-on or checked bags. If you’re not checking your bag — or flying internationally and need to show your passport to an agent — you can often skip the physical counter line and head straight to TSA inspection if you’ve already checked in online and have your boarding pass on your phone. Even if you have to visit the counter to check a bag, some airlines have special shortcut lines at the airport for those who already have their boarding pass. And if you have an international leg, most airlines will allow you to fill out your passport information online during check-in, so the process can be even quicker. 

You Make Sure You Actually Have a Seat

According to the U.S. Department of Transportation, airlines are allowed to oversell flights to compensate for the fact that many travelers no-show for their flights. You never want to be the person who arrives at the airport only to realize that you don’t have a seat if the plane is overbooked. If you’re the last person to check in, you may be the passenger who is cut from the roster and bumped to a later flight, so checking in early can help you avoid this scenario.