Where Every Major US Airline Ranks in 2021

WalletHub recently compared the nine largest U.S. airlines along with a pair of regional carriers across as many as 17 different metrics ranging from cancellation and delay rates to baggage mishaps and in-flight comfort. The financial website also analyzed safety, pet-friendliness and cost. Here's how the 11 carriers stack up as of spring 2021.

Frontier Airlines rounds out the rankings in 11th place with an overall WalletHub score of 37.09. The Denver-based ultra-low-cost carrier performs well when it comes to airfare, of course, but takes big hits in terms of in-flight experience and consumer complaint rate.

Despite ranking toward the bottom, JetBlue was found to be the most comfortable domestic carrier out there, leading the way in terms of the in-flight experience. After all, the airline offers passengers free amenities such as Wi-Fi and extra legroom as well as complimentary snacks and beverages.

American Airlines ranks the worst of the Big Four U.S. carriers. American turned in a lackluster performance in terms of reliability, edging out only Frontier Airline and Envoy Air. Fortunately, the carrier plans to reintroduce full beverage service in all domestic premium cabins and the main cabin as early as May 1, with shorter routes bringing back drinks on June 1.

United Airlines manages to top rival American but has some ground to make up with an overall WalletHub score of just 45.7. Still, United is the second-most reliable airline among the 11 that the website looked at and is also among the most comfortable, tying American with a score of 4.5.

Texas-based regional airline and American Airlines Group subsidiary Envoy Air is tied for being the most pet-friendly carrier in America, with no incidents. The carrier also turned in the industry's lowest consumer complaint rate in 2020. Envoy Air was also the runner-up as the safest airline in 2020.

Despite maintaining the top spot as the most punctual carrier in the U.S. for a 17th consecutive year, Hawaiian Airlines ranks just sixth overall. While the airline doesn't win any one category, it performs well in terms of in-flight comfort and safety. Interestingly, only Frontier had a worse consumer complaint rate in 2020.

Regional carrier SkyWest Airlines-which has contracts with Alaska Airlines (Alaska SkyWest), American (American Eagle), Delta Air Lines (Delta Connection) and United (United Express)-performs surprisingly well in terms of consumer satisfaction and pet-friendliness and is relatively steady when it comes to reliability, helping it reach fifth overall for 2021.

Low-cost carrier Southwest Airlines was determined to be the most reliable of all U.S. airlines, turning in the lowest rate of cancelations, delays, mishandled luggage and denied boardings. Southwest also ties Alaska Airlines for the second-most comfortable carrier and remains one of the most affordable.

Unsurprisingly, Spirit Airlines was found to be the cheapest of the 11 carriers that WalletHub analyzed. The budget-friendly airline came out on top based on passenger revenue per available seat mile (PRASM), which was obtained by dividing passenger revenue by the product of the number of available seats and the number of miles flown.

Delta Air Lines has consistently been one of the best North American carriers for safety, service and convenience in the time of COVID-19 so it's no surprise to see it ranks toward the top of WalletHub's list. Delta is relatively wallet-friendly in 2021 and isn't far behind JetBlue in terms of the in-flight experience.

Alaska Airlines is the best domestic airline in 2021, based on WalletHub's comprehensive research. The carrier earned an overall score of 56.54 and was also the safest in 2020, earning a safety score of 20.55. The category takes into consideration average fleet age, face mask availability, blocked middle seat policy and the number of accidents, among other factors. Alaska also tied SkyWest and Envoy as the most pet-friendly.