These United Airlines passengers got switched to better seats for free: How you can do it

United Airlines said more than 18,000 passengers managed to avoid a middle seat last month, even when they thought all hope was lost.

The airline announced a new feature in its app in March that allows travelers to designate a seating preference in their reservation and get moved automatically, for free, if a better seat opens on their flight. The options include window, aisle, exit or bulkhead rows.

Almost 40% of travelers who made the requests were able to move into their desired location prior to departure, according to United.

United will move passengers into their preferred seat type if it becomes available in the same class of service as their original seat up to 12 hours before departure.

Most travelers go out of their way to avoid the middle seat, but seasoned flyers often have preferred rows or specific seats that are to their liking.

Sites like aeroLOPA can help passengers figure out which seat has the best window alignment, for example, and can inform how they set their preferences in United’s app.

Zach Wichter is a travel reporter for USA TODAY based in New York. You can reach him at zwichter@usatoday.com.

This article originally appeared on USA TODAY: This United Airlines app feature helps you get a better seat for free