World's top 10 busiest routes by number of flights in 2021. All of the top 10 routes were domestic, and most were in Asia.
1. Jeju to Seoul Gimpo, South Korea
Frequency 2021: 85,880 flights
Frequency Change vs 2019: +0.30%
Major Airlines: Korean Air, Asiana Airlines, Jeju Air, T'way Air
Despite another year full of uncertainty amid the COVID-19 pandemic, the domestic route between Jeju and Seoul Gimpo, often known as the ‘Hawaii of South Korea', maintained its position for consecutive years. The 450-km domestic route is popular among leisure travellers, and around 235 flights were operated each day in 2021.
Nine carriers competed in the GMP-CJU market in 2021, led by Korean Air which offered about 4 million two-way seats. A further 3.9 million were available onboard Asiana Airlines, while Jeju Airlines provided 2.9 million seats.
In total, capacity between the destinations was almost 17.1 million seats—down by just 1.9% on the figure offered in 2019.
Most of the flights were operated by Boeing 737s and Airbus A320 family jets, together with the A220 with Korean Air. Hi Air's ATR-72s operated the only turboprop flight. Almost one-quarter of the flights were operated by Korean Air Airbus A330 and Asiana Boeing 767 widebodies.
2. Seoul Gimpo to Busan, South Korea
Frequency 2021: 34,897 flights
Frequency Change vs 2019: +64%
Major Airlines: Air Busan, Korean Air, Air Seoul
The second busiest route is another South Korean domestic route between Seoul Gimpo and Busan. The flight frequency was increased by a staggering 65% compared to 2019. More than 90 flights were operated each day between the airports in 2021. The market was highly dominated by Airbus A320 family jets and Boeing 737s, with a handful of flights operated by Korean A220s.
Seoul to Busan saw a significant boost in frequency amid the pandemic as air transport was chosen as the safest and quickest means of transport. The newest observatory in Busan, Busan X The Sky and the Osiria Tourist Complex in Gijang-gun further boosted leisure travel, hugely boosting the flight frequency.
3. Jeddah to Riyadh, Saudi Arabia
Frequency 2021: 32,405 flights
Frequency Change vs 2019: -14.80%
Major Airlines: Saudia, Flyadeal, Flynas
Saudi Arabian domestic route between King Abdulaziz International Airport, Jeddah and King Khalid International Airport, Riyadh ranked the third busiest route in 2021.
Aircraft types on this route range from the Airbus A320 family jets to Boeing 737s. Saudia used Airbus A330 and Boeing 787 Dreamliner widebodies regularly on flights between the two cities.
4. Fukuoka to Tokyo Haneda, Japan
Frequency 2021: 32,400 flights
Frequency Change vs 2019: -18.8%
Major Airlines: ANA, Japan Airlines, Skymark Airlines, StarFlyer
Japan's domestic route from Fukuoka to Tokyo Haneda has been consistently being one of the world’s busiest routes in both number of passengers and number of flights.
Many aircraft ranging from Airbus and Boeing narrowbodies to widebodies were used on this route. Along with Boeing 737s, Japan Airlines used Airbus A350s, Boeing 777s and 787s. ANA also operated a mix of narrowbodies and Boeing 767, 787 widebodies.
5. Sapporo New Chitose to Tokyo Haneda, Japan
Frequency 2021: 31,495 flights
Frequency Change vs 2019: -20.3%
Major Airlines: ANA, Japan Airlines, Air Do, Skymark Airlines
Rounding up the top five is another Japanese route between Sapporo and Tokyo Haneda. The fastest means of transport between the largest city of Japan's northernmost island of Hokkaido and Tokyo is by air. More than 85 daily flights were operated between the cities in 2021.
The majority of the flights were operated by ANA and Japan Airlines, operating a mix of narrowbody and widebody jets. Japan Airlines operated most of the flights using Airbus A350, Boeing 767 and 777 widebodies, whereas ANA used Boeing 767 and 787s on this route along with narrowbody aircraft.
6. Hanoi to Ho Chi Minh City, Vietnam
Frequency 2021: 29,347 flights
Frequency Change vs 2019: -38.2%
Major Airlines: Bamboo Airways, Vietnam Airlines, Vietjet Air
The Vietnamese domestic route between Hanoi and Ho Chi Minh City is the sixth busiest route in 2021. Although flight frequencies plunged by 38.2%, almost 80 flights were operated daily in 2021.
Both narrow and widebody jets served the high-demand route between Hanoi and Ho Chi Minh City. Bamboo Airways and Vietnam Airlines operated around one-quarter of the flights using Boeing 787 Dreamliners, whereas other flights were operated by narrowbody jets. Vietnam Airlines also used Airbus A350s on some flights.
7. Shanghai Hongqiao to Shenzhen, China
Frequency 2021: 29,250 flights
Frequency Change vs 2019: -2.0%
Major Airlines: China Eastern, China Southern, Shenzen Airlines, etc.
The Chinese route between Shanghai Hongqiao and Shenzhen was the seventh busiest route in 2021. As many as seven Chinese airlines such as China Southern, China Eastern, and Spring Airlines operate flights between the two cities.
While most of the airlines used Airbus and Boeing narrowbodies to operate this route, China Eastern heavily used Airbus A330s to ensure high seats per flight. Widebodies were used by other airlines on multiple occasions.
8. Beijing Capital to Shanghai Hongqiao, China
Frequency 2021: 28,120 flights
Frequency Change vs 2019: -5.5%
Major Airlines: Air China, Hainan Airlines, China Eastern
Shanghai Hongqiao Airport mainly serves domestic and regional flights and hosts another busiest route globally. Three major Chinese airlines operated equivalent to 77 daily flights in 2021.
Many aircraft were used on this route, with China Eastern Airlines and Air China operating the most diverse fleet of Airbus A330, A350, Boeing 777, and narrowbody jets. Besides narrowbodies, China Southern used Airbus A330s on some of the flights.
9. Cancun to Mexico City, Mexico
Frequency 2021: 27,228 flights
Frequency Change vs 2019: -14.0%
Major Airlines: Aeromexico, Viva Aerobus, Volaris
Over to North America, the route between Cancun and Mexico City was the busiest American route in 2021, with over 70 daily flights. This route is heavily dependent on Airbus A320 family jets and Boeing 737s.
10. Jakarta to Denpasar-Bali, Indonesia
Frequency 2021: 26,959 flights
Frequency Change vs 2019: -9.10%
Major Airlines: Garuda Indonesia, Batik Air, Lion Air, Citilink
Indonesia's domestic route between Jakarta and Bali was the tenth busiest route in 2021. While the Boeing 737 and Airbus A320 were common on the market, Garuda Indonesia deployed A330 and Boeing 777 on the route. Standing out among others, Citilink's ATR-72s flight was the only turboprop flight in operation.
Top 50 busiest routes in the world in 2021 by flight frequency: Source OAG Schedules Analyser
| Rank | Airport pair | Frequencies | Change vs 2019 | |||
|---|---|---|---|---|---|---|
| 1 | Jeju (CJU) | South Korea | Seoul Gimpo (GMP) | South Korea | 85880 | 0.3% |
| 2 | Seoul Gimpo (GMP) | South Korea | Busan (PUS) | South Korea | 34897 | 64.0% |
| 3 | Jeddah (JED) | Saudi Arabia | Riyadh King Khalid (RUH) | Saudi Arabia | 32405 | -14.8% |
| 4 | Fukuoka (FUK) | Japan | Tokyo Haneda (HND) | Japan | 32400 | -18.8% |
| 5 | Sapporo New Chitose (CTS) | Japan | Tokyo Haneda (HND) | Japan | 31495 | -20.3% |
| 6 | Hanoi (HAN) | Vietnam | Ho Chi Minh City (SGN) | Vietnam | 29347 | -38.2% |
| 7 | Shanghai Hongqiao (SHA) | China | Shenzhen (SZX) | China | 29250 | -2.0% |
| 8 | Beijing Capital (PEK) | China | Shanghai Hongqiao (SHA) | China | 28120 | -5.5% |
| 9 | Cancun (CUN) | Mexico | Mexico City Juarez (MEX) | Mexico | 27228 | -14.0% |
| 10 | Jakarta (CGK) | Indonesia | Denpasar-Bali (DPS) | Indonesia | 26959 | -9.1% |
| 11 | Mumbai (BOM) | India | Delhi (DEL) | India | 26738 | -40.5% |
| 12 | Dar Es Salaam (DAR) | Tanzania | Zanzibar (ZNZ) | Tanzania | 26201 | 0.5% |
| 13 | Guangzhou (CAN) | China | Chengdu (CTU) | China | 26123 | -0.6% |
| 14 | Cape Town (CPT) | South Africa | Johannesburg (JNB) | South Africa | 24674 | -30.0% |
| 15 | Bogota (BOG) | Colombia | Cartagena (CTG) | Colombia | 22094 | -33.1% |
| 16 | Jeju (CJU) | South Korea | Busan (PUS) | South Korea | 21962 | -0.4% |
| 17 | Belize City Goldson (BZE) | Belize | Dangriga (DGA) | Belize | 21895 | -9.0% |
| 18 | Jakarta (CGK) | Indonesia | Medan Kuala Namu (KNO) | Indonesia | 21722 | 4.3% |
| 19 | Melbourne (MEL) | Australia | Sydney Kingsford Smith (SYD) | Australia | 20674 | -62.1% |
| 20 | Chengdu (CTU) | China | Beijing Capital (PEK) | China | 20542 | -16.4% |
| 21 | Guangzhou (CAN) | China | Hangzhou (HGH) | China | 20426 | 3.8% |
| 22 | Tokyo Haneda (HND) | Japan | Osaka (Itami) (ITM) | Japan | 20347 | -9.7% |
| 23 | St Barthelemy (SBH) | Saint Barthelemy | St Maarten (SXM) | St Maarten (dutch Part) | 20216 | -22.2% |
| 24 | Guangzhou (CAN) | China | Shanghai Hongqiao (SHA) | China | 19957 | -2.5% |
| 25 | Jakarta (CGK) | Indonesia | Surabaya (SUB) | Indonesia | 19734 | -39.6% |
| 26 | Jakarta (CGK) | Indonesia | Makassar (UPG) | Indonesia | 19690 | -43.3% |
| 27 | Chongqing (CKG) | China | Shenzhen (SZX) | China | 19216 | 11.6% |
| 28 | Los Angeles (LAX) | US | San Francisco (SFO) | US | 19211 | -42.3% |
| 29 | Bengaluru (BLR) | India | Delhi (DEL) | India | 19011 | -31.2% |
| 30 | Chengdu (CTU) | China | Shenzhen (SZX) | China | 18627 | -0.1% |
| 31 | Tokyo Haneda (HND) | Japan | Okinawa Naha (OKA) | Japan | 18255 | -16.5% |
| 32 | Hangzhou (HGH) | China | Shenzhen (SZX) | China | 17739 | -1.2% |
| 33 | Belize City Goldson (BZE) | Belize | Placencia (PLJ) | Belize | 17653 | 9.7% |
| 34 | Bogota (BOG) | Colombia | Medellin (MDE) | Colombia | 17643 | -25.4% |
| 35 | Las Vegas (LAS) | US | Los Angeles (LAX) | US | 17443 | -33.1% |
| 36 | Cheongju (CJJ) | South Korea | Jeju (CJU) | South Korea | 17220 | 16.0% |
| 37 | Sao Paulo Congonhas (CGH) | Brazil | Rio de Janeiro Santos Dumont (SDU) | Brazil | 17200 | -53.4% |
| 38 | Durban King Shaka (DUR) | South Africa | Johannesburg (JNB) | South Africa | 16830 | -33.4% |
| 39 | Honolulu (HNL) | US | Kahului (OGG) | US | 16487 | -32.7% |
| 40 | Mexico City Juarez (MEX) | Mexico | Monterrey (MTY) | Mexico | 16203 | -42.3% |
| 41 | Bogota (BOG) | Colombia | Cali (CLO) | Colombia | 16160 | -23.9% |
| 42 | Jinghong (JHG) | China | Kunming (KMG) | China | 16122 | -24.7% |
| 43 | Delhi (DEL) | India | Srinagar (SXR) | India | 16041 | 54.3% |
| 44 | Mashhad (MHD) | Iran | Tehran Mehrabad (THR) | Iran | 15639 | -8.0% |
| 45 | Beijing Capital (PEK) | China | Shenzhen (SZX) | China | 15551 | -34.5% |
| 46 | Abuja (ABV) | Nigeria | Lagos (LOS) | Nigeria | 15519 | 3.5% |
| 47 | Guadalajara (GDL) | Mexico | Mexico City Juarez (MEX) | Mexico | 15153 | -43.9% |
| 48 | Belize City Goldson (BZE) | Belize | San Pedro (SPR) | Belize | 15117 | 1.6% |
| 49 | Portland (PDX) | US | Seattle-Tacoma (SEA) | US | 15086 | -24.5% |
| 50 | Kolkata (CCU) | India | Delhi (DEL) | India | 15025 | -27.5% |
Sources: Routes Online and OAG