The best airlines in the US are based on flight data from the US Department of Transportation.

mainline airlines like American and Southwest, and low-cost carriers like Spirit and Frontier, were ranked from best to worst by the company.

SkyWest Airlines and Envoy Air were included because they make up at least 1% of domestic scheduled service and report data to the DOT.

Each airline was scored based on 16 metrics, including baggage, departures, and complaints, animal-related incidents, inflight comfort, and safety. Delays, legroom, denied boardings, and price were included in the subcategories.

While price is a common dealbreaker for many consumers, WalletHub noted that its report examines overlooked aspects of air travel to help travelers make more informed decisions.

It wouldn't be right to penalize an airline that charges for drinks if its tickets are cheaper than those from another airline.

The best and worst airlines in the US were determined by WalletHub from the four major categories. The number of customer complaints and the rate of delays were some of the criteria used to calculate scores.

The company ranked the points from each category to come up with an overall performance rank. Southwest came in last with just 30.60 points earned, while Delta earned the highest score of 70.48 out of 100.

The weight of each metric and its calculation into the overall score was based on the company's subjective view, as was the maximum number of points an airline could earn. It said points were allocated based on common sense.

The company also gave awards for cheapest airline, safest airline, most reliable airline, the best airline for pets, and most comfortable airline.

Delta took home the most medals, including being the best overall US airline, the most reliable, and tied for the safest for animals. The comfort and affordability spots went to Frontier and JetBlue, respectively.

Here is a closer look at the best and worst US airlines.

11. Southwest Airlines

View from the wing of a Southwest Airlines Boeing 737 Max 8 aircraft on the tarmac. Ashlee D. Smith/Southwest Airlines

Southwest was the worst airline in several categories, including being the least reliable and the least safe. Southwest got a score of 7.84 out of 50 for reliability, while the top performers, including Delta and Hawaiian, scored above 30.

Southwest earned a score of 26.80 in the previous year, but that score was 888-282-0465 888-282-0465 888-282-0465. The airline had a multi-day meltdown in October 2021, which left thousands of passengers stranded.

The airline's low safety rating was due to an uncontained engine failure that resulted in the death of a passenger, which forced WalletHub to deduct points.

10. American Airlines

American aircraft.
American aircraft.
Airbus

American was last on the list, earning low scores in reliability, price, and safety. The carrier's low safety rating was caused by at least 50 passenger or employee injuries that required medical care in 2021, according to the data.

The carrier earned a comfort score of 4 out of 5, though it did not earn a reliability score.

9. JetBlue Airways

JetBlue A320 aircraft.
JetBlue A320 aircraft.
Marcus Mainka/Shutterstock

The Wall Street Journal named JetBlue the worst US airline due to poor on-time performance and a high number of passenger complaints.

In terms of customer complaints, the data from WalletHub ranked fourth, with a reliability score of 16.22 out of 50.

Not all is bad for the airline. Inflight entertainment, snacks, and beverages, as well as free wi fi, were some of the perks offered by the carrier. The carrier has the most legroom in the economy.

8. Frontier Airlines

Frontier Airlines
Frontier Airlines
Carlos Yudica

Frontier came in last for comfort due to a lack of inflight amenities, like free snacks and drinks, as well as being low in terms of reliability.

According to travel magazine AFAR, the lowest legroom in the US is offered by the carrier.

The cheapest plane tickets of any other carrier were offered by Frontier. The data shows that Frontier's airfare was 3.53 cents per mile.

7. United Airlines

A United Airlines plane.
A United Airlines airplane is seen at the Newark Liberty International Airport in Newark, New Jersey, United States.
ayfun Coskun/Anadolu Agency via Getty Images

The third-best reliability score of 26.67 out of 50 and a high comfort score of 4.5 out of 5 was received by United.

Its high number of passenger complaints can be attributed to its low ranking. According to DOT data, United had 3,581 complaints in the year of 2021, which came out to 29.73 complaints per 100,000 passengers.

6. SkyWest Airlines

SkyWest Airlines Bombardier CRJ200 aircraft
A SkyWest Airlines Bombardier CRJ200 aircraft.
Heather Dunbar / Shutterstock.com

SkyWest, which flies on behalf of United, Delta, American, and Alaska, earned high rankings for pet-friendliness and customer satisfaction. DOT data shows that the carrier has a rate of 0.92 complaints per 100,000 passengers.

Skywest is a regional carrier that flies for four other carriers.

5. Spirit Airlines

Spirit Airlines A319 aircraft.
Spirit Airlines A319 aircraft.
Marcus Mainka/Shutterstock

Rounding out the top five carriers, Spirit Airlines performed well in terms of affordability and safety.

The carrier has an average airfare of 3.82 cents per mile. The airline received a score of 19.99 out of 50 for reliability, which is average compared to other airlines.

Unlike Frontier, Spirit did not offer free amenities inflight, except for a seat and a personal item.

4. Envoy Air

American Eagle regional aircraft.
American Eagle regional aircraft.
Markus Mainka/Shutterstock

Envoy is a wholly-owned subsidiary of American and is one of the top-performing operators. Southwest had a score of 30.60, but the airline earned an overall score of 60.46 out of 100. It scored high for pet safety.

Envoy had an average fare of 12.42 cents per mile. The airfare increases due to the carrier flying on behalf of American to small markets that have higher operating costs.

3. Alaska Airlines

Alaska Airlines.
Alaska Airlines.
Alaska Airlines

The third-best airline in the US is Alaska. The airline scored high in terms of reliability, comfort, and price, and earned the title of the safest airline.

The airline scored 4.5 out of 5 for comfort, tying with Delta and just losing out to JetBlue.

2. Hawaiian Airlines

Hawaiian Airlines Boeing 767
Hawaiian Airlines Boeing 767
Angel DiBilio/Shutterstock

Hawaiian scored high in affordability, reliability, and safety. The airline scored 2 out of 5 in terms of comfort.

The airline had the second-highest number of passenger complaints with 37.63 per 100,000 passengers. The airline received a high score due to its on-time performance.

1. Delta Air Lines

Delta Air Lines aircraft.
Delta Air Lines aircraft.
On The Run Photo/Shutterstock

Delta was named the best carrier in the US. The most reliable airline is based in Atlanta and tied for second with Hawaiian.

The airline reported no animal-related incidents in 2021. The airline had one of the lowest rates of consumer complaints.