- Airlines worldwide have been on a rollercoaster of schedule and operational challenges since March 2020.
- Carriers have shrunk and expanded throughout COVID-19, and today's industry looks different than it did pre-pandemic.
- Aviation data firm OAG shared with Insider the world's biggest airlines based on seats available in 2021 — take a look.
Over the past two and a half years, the airline industry has changed dramatically.
Starting in March 2020, the COVID-19 pandemic forced carriers around the globe to shrink and modify their schedules as travel halted and countries closed their borders. Pilots sought early retirement, employees were furloughed, and aircraft were parked.
However, the strong post-pandemic demand is flipping the industry on its head. With travel rebounding faster than expected, airlines are making moves to keep up, like buying new planes, flying new routes, and launching aggressive hiring campaigns to get more feet on the ground and in the air to keep the operation running smoothly.
Globally, airlines carried an estimated 2.2 billion people and flew 22.2 million flights in 2021, reported research company Finances Online, citing data from the International Aviation Transportation Agency (IATA). That compares to 1.8 billion in 2020, which was just 40% of the 4.5 billion carried in 2019, per IATA.
With all the upheaval, which airlines are now the largest in the world? Turns out the US' "Big Four" airlines, including American Airlines, United Airlines, Delta Air Lines, and Southwest Airlines, as well as several Chinese carriers, made the top-20 list with hundreds of millions of seats offered in 2021, according to data from London-based aviation analytics firm Official Airline Guide (OAG).
The organization also provided 2018's data set to Insider in 2019, which revealed American Airlines as the world's largest carrier. Since then, the rankings have changed, with Southwest Airlines becoming the world's largest carrier in terms of seats. Several airlines that made the top 20 list in 2018 offered significantly fewer seats in 2021.
Meanwhile, there are a handful of carriers, like JetBlue Airways and Hainan Airlines, that were not part of the 2018 data set but increased capacity last year to make the list.
Here are the world's 20 biggest airlines in the world by the number of seats made available to customers:
20. Alaska Airlines
Country: USA
2021 Capacity: 33,645,148 seats
2018 Capacity: 54,574,295 seats
19. Shandong Airlines
Country: China
2021 Capacity: 33,735,751 seats
2018 Capacity: Not in the 2018 top 20 dataset
18. Hainan Airlines
Country: China
2021 Capacity: 38,230,597 seats
2018 Capacity: Not in the 2018 top 20 dataset
17. Xiamen Airlines
Country: China
2021 Capacity: 39,087,022 seats
2018 Capacity: Not in the 2018 top 20 dataset
16. Sichuan Airlines
Country: China
2021 Capacity: 39,294,914 seats
2018 Capacity: Not in the 2018 top 20 dataset
15. Easyjet
Country: UK
2021 Capacity: 39,490,376 seats
2018 Capacity: 100,082,969 seats
14. Shenzhen Airlines
Country: China
2021 Capacity: 39,727,188 seats
2018 Capacity: Not in the 2018 top 20 dataset
13. JetBlue Airways
Country: USA
2021 Capacity: 40,356,063 seats
2018 Capacity: Not in the 2018 top 20 dataset
12. Spirit Airlines
Country: USA
2021 Capacity: 40,622,515 seats
2018 Capacity: Not in the 2018 top 20 dataset
11. Turkish Airlines
Country: Turkey
2021 Capacity: 45,249,215 seats
2018 Capacity: 93,109,025 seats
10. Ryanair
Country: Ireland
2021 Capacity: 48,696,471 seats
2018 Capacity: 142,540,776 seats
9. Skywest Airlines
Country: USA
2021 Capacity: 48,696,471 seats
2018 Capacity: 142,540,776 seats
8. IndiGo
Country: India
2021 Capacity: 72,444,166 seats
2018 Capacity: 74,570,054 seats
7. Air China
Country: China
2021 Capacity: 75,905,153 seats
2018 Capacity: 90,531,776 seats
6. United Airlines
Country: USA
2021 Capacity: 97,220,490 seats
2018 Capacity: 193,981,547 seats
5. China Eastern Airlines
Country: China
2021 Capacity: 115,625,762 seats
2018 Capacity: 122,917,175 seats
4. China Southern Airlines
Country: China
2021 Capacity: 123,472,958 seats
2018 Capacity: 131,972,745 seats
3. Delta Air Lines
Country: USA
2021 Capacity: 143,180,744 seats
2018 Capacity: 233,758,798 seats
2. American Airlines
Country: USA
2021 Capacity: 151,146,489 seats
2018 Capacity: 256,928,663 seats
1. Southwest Airlines
Country: USA
2021 Capacity: 168,852,981 seats
2018 Capacity: 209,526,838 seats