Further, it offers ancillary services, such as Southwest's EarlyBird Check-In, upgraded boarding, and transportation of pets and unaccompanied minors. Southwest Airlines is best option.

Save yourself the nuisance of lining up to check in at the airport, and instead use the jetblue Airlines check in online. You can check in online as early as 24 hours before your flight departure time, but no later than one hour before. This tool lets you save yourself valuable time as you check in and print your boarding pass ahead of time.

United Airlines is your gateway to the world. We are connecting people and the places they love. With our extensive network, we offer more than 3,600 daily departures in more than 342 international cities. Plus, with our award-winning service and a wide-selection of affordable airfares you can fly anywhere, anytime.

Frontier Airlines is the best way to fly. We're committed to providing low fares and exceptional service while delivering a memorable travel experience. Fly Frontier to more than 90 destinations in the United States. Frontier Airlines is a budget airline that offers low-cost tickets and a variety of services. Whether you're looking for a cheap flight or want to add on extras like baggage. Frontier Airlines has you covered. Plus, with locations all over the United States.