Southwest is the worst airline in the US, according to a new study take a look at how the 11 biggest US airlines rank

WalletHub analyzed 2022 flight data from the US Department of Transportation to come up with its ranking. The ranking includes 11 airlines, including two regional carriers.

The regional carriers were included as they made up at least 1% of domestic scheduled service, Jill Gonzalez, an analyst with WalletHub, told Insider.

The nine national airlines were selected based on the highest passenger revenue, Gonzalez said.

WalletHub scored each airline based on 14 metrics across four categories. The first category, baggage and departures, divided 50 points across subcategories that included canceled flights, delays, mishandled baggage reports, and denied boardings. The second category was animal-related incidents, with up to 5 points.

The third category allocated 15 points for in-flight comfort and cost, which was divided between five subcategories, including legroom, entertainment options, Wi-Fi availability, complimentary refreshments, and price. The last category was safety for 30 points, which factored in the number of fatal injuries in aviation accidents, the number of injuries in aviation accidents, and the number of aviation accidents — the data is measured from 2017 to 2022.

The total number of points possible is 100.

"We generally allocated points based on common sense, with the best value for each metric being awarded full points, the worst value receiving zero points and values in between receiving a proportional score relative to those endpoints," Gonzalez said.

In each of the following slides, Insider listed out three categories — delays, denied boardings, and price — that contributed the most to an airline's total score. Take a look at how these US airlines rank, from the lowest to highest scores.

Delays: 3.49/18

Denied boardings: 2.95/15

Price: 2.79/10

Total score: 23.39/100

Southwest is ranked the worst airline in the US for the second year in a row by WalletHub. The airline Faried poorly in nearly all categories, with the exception of comfort-related categories like leg room, entertainment options, and Wi-Fi availability. Southwest is the only airline to score zero points in two safety-related categories, which means that at least 1 fatality and at least 50 injuries have occurred on its flights from 2017 to 2022.

Southwest is certified as a four-star airline by the airline ranking site Skytrax. On Skytrax's customer reviews site, it has an average rating of four out of 10 over 1,700 reviews. Its recent reviews are mixed.

One passenger, who flew with the airline in April, wrote that Southwest's "seats were like rocks"and their return flights were delayed, forcing them to wait six hours for their flight to Orlando, Florida. But another passenger, who flew with the airline in April, had a much better experience. They praised Southwest for the smooth flight by the pilot, whom the passenger described as "patient and kind" for taking photos with their kids.

Delays: 1.13/18

Denied boardings: 0/15

Price: 8.21/10

Total score: 45.13/100

Frontier scored well in two safety-related categories, which means that fatalities or injuries from aircraft accidents were exceptionally rare. But the airline fared poorly in comfort-related categories, including legroom, entertainment options, Wi-Fi availability, and complimentary refreshments — scoring zero in all these metrics.

Frontier is certified as a three-star airline by Sktrax. On Skytrax's passenger reviews site, it has an average rating of two out of 10 over 3,100 reviews. Its recent reviews are mostly negative.

One passenger, who flew with the airline in April, complained that Frontier requires passengers to "size their bags before boarding," and that they felt harassed by staff. Another passenger, who flew a connecting route in April, echoed these complaints, writing that Frontier has "zero customer service" and has "predatory practices" on baggage pricing.

Delays: 6.29/18

Denied boardings: 6.77/15

Price: 1.79/10

Total score: 47.06/100

American scored well in comfort-related categories, including legroom, entertainment options, and complimentary refreshments. But American scored poorly in terms of animal-related incidents, with 0.26 out of a possible five points. This meant that the ratio of lost, injured, or dead animals transported by the airline was relatively high.

American is certified as a three-star airline by Skytrax. On Skytrax's passenger reviews site, the airline has an average rating of two out of 10 over 5,400 reviews.

One passenger, who flew with the airline in April, had a negative experience, writing that his suitcase was damaged and he wasn't compensated for it. But another passenger had a positive experience flying with American, praising the airline for a smooth flight despite offering deep discounts on its tickets.

Delays: 10.57/18

Denied boardings: 0.62/15

Price: 0/10

Total score: 52.25/100

Envoy Airlines is one of two regional airlines on WalletHub's list. Envoy scored well in comfort-related categories like legroom and entertainment options, and fleet age — which means its jets are relatively new. But Envoy has the lowest score in terms of mishandled baggage reports — zero out of a possible nine points— which means it has the highest ratio of lost, damaged, and delayed baggage among all airlines included in the list.

The airline is the regional carrier for American Airlines, and operates only business jets. It is not listed or rated on Skytrax.

On the airline review site Airlines Inform, Envoy has mixed reviews, with an average rating of 2.63 out of five. One passenger who flew with the airline in May 2022 had a positive experience with the airline, writing that the "flight was on time, and we got a drink and snack." Another passenger, who flew on five flights with Envoy in December 2022, said he had no issues with any of the flights.

Delays: 0/18

Denied boardings: 13.72/15

Price: 3.82/10

Total score: 55.46/100

Jetblue scored well in comfort-related categories including legroom, entertainment options, and Wi-Fi availability. But the airline scored the lowest in terms of delays — zero out of a possible 18 — which meant that it had the highest percentage of delayed flights among airlines on the list.

Jetblue is certified as a four-star airline by Skytrax. On Skytrax's passenger reviews site, it has a customer rating of three out of 10 over 1,400 reviews.

Jetblue's recent reviews are mostly negative. One passenger who flew with the airline in April said staff were "unprofessional, unpleasant, and just lazy." Another passenger who flew from Jamaica to New York in April said they had a "horrible experience" as their flight was delayed, and that the cheaper prices aren't worth it.

Delays: 2/18

Denied boardings: 14.91/15

Price: 3.81/10

Total score: 57.14/100

Hawaiian scored well in comfort-related categories, including legroom, entertainment options, and complimentary refreshments. But the airline scored poorly — zero out of a possible five points — in the category for animal-related incidents. This meant it had the highest number of animals that died, got injured, or were lost while being transported, among airlines on the list.

Hawaiian is certified as a three-star airline by Skytrax. According to Skytrax's passenger review site, it has a rating of five out of 10 from 500 reviews.

Recent reviews are mostly negative. One passenger who flew a domestic route with the airline in April said they "experienced delays and canceled flights over multiple days." Another passenger who flew business class in March said they experienced a "big change in quality" and the airline doesn't have friendly service or flexible reservations.

Delays: 9.18/18

Denied boardings: 12.67/15

Price: 3.72/10

Total score: 59.03/100

Alaska scored well in comfort-related categories, including legroom and entertainment options. But it had the lowest score — zero out of eight possible points — in terms of canceled flights. This means that out of all the airlines on the list, Alaska had the highest percentage of flight cancelations.

According to Skytrax, Alaska is certified as a three-star airline. On Skytrax's passenger reviews site, the airline has an average rating of four out of 10.

One passenger, who traveled with the airline in April, said premium seats were "super narrow and not worth the extra cost." Another passenger, who flew in March, had a better experience thanks to the flight attendants who were "pretty good about making you comfortable."

Delays: 8.46/18

Denied boardings: 14.71/15

Price: 2.38/10

Total score: 62.83/100

United scored well in comfort-related categories, including legroom, entertainment options, and complimentary refreshments. But the airline had one of the lowest scores in the aviation incidents and accidents category, which measures the ratio of the airline's accidents to its total operated flights from 2017 to 2022. United scored just 0.46 out of six in the category.

United is a three-star airline, according to Skytrax. It has an average score of three out of 10 over 4,400 reviews on Skytrax's passenger review site.

Recent reviews are mixed, with one passenger who flew in April praising United for the "excellent service", noting that they want to continue booking with the airline in the future. Another passenger, who flew to the US in April from Trinidad and Tobago, said they had problems with their connecting flight, warning other travelers to avoid flying with United as they "will never make it on time."

Delays: 7.84/18

Denied boardings: 12.26/15

Price: 5.48/10

Total score: 63.71/100

Skywest is the other regional airline on the list, serving short-haul flights for American, Delta, Alaska, and United. While the airline scored highly in categories like denied boardings, which means it managed overbooked flights well, it did poorly in comfort-related categories, including legroom and entertainment options.

Skywest is not officially rated by Skytrax. According to its passenger reviews site, it has a rating of seven out of 10 over 38 reviews, but no new reviews have been made since 2013.

On the general reviews site Customer Service Scoreboard, Skywest has mixed reviews. One passenger who flew in January 2022 said it was the worst trip they had experienced, as one flight attendant was "rude and indignant." Another passenger said the airline was "understaffed" and had "old planes."

Delays: 8.11/18

Denied boardings: 7.14/15

Price: 8.29/10

Total score: 66.57/100

Spirit scored well in WalletHub's safety criteria with a perfect mark in fatal injuries in aviation accidents. This means that Spirit has no fatalities from aircraft-related issues.

According to Skytrax, Spirit is certified as a 3-star low-cost airline. On Skytrax's passenger reviews site, the airline has a rating of two out of 10 from 4,700 passengers.

Spirit has mostly negative reviews online from passengers. One passenger who flew in economy in April said that the airline's flight cancellation left him, his wife, and two-year-old son stranded in Las Vegas. Another passenger who flew with the airline in April complained about the airline's four-hour delay on his layover, adding that he will never "be flying Spirit ever again."

Delays: 10.04/18

Denied boardings: 15/15

Price: 1.79/10

Total score: 66.79/100

Delta was named the best US airline by WalletHub for the second year in a row. Delta excelled in several categories, including a perfect score on the "denied boardings" metric, which meant the airline manages oversold flights well.

According to Skytrax, Delta is certified as a 3-star airline. On Skytrax's customer reviews site, it has a rating of 4 out of 10 from over 2,700 reviews.

Passengers have mixed reviews of the airline. One passenger, who traveled on Delta in April, said that customer service was "rude and unhelpful," and noted that a fragile item the staff forced him to check in ended up damaged. Another passenger, who flew in first class in April, said that flight attendants were "attentive and friendly," and that she enjoys flying with the airline.