Fascinating map reveals the world's busiest international flight routes, with Kuala Lumpur to Singapore Changi No. 1 and London Heathrow to JFK in eighth place

Kuala Lumpur to Singapore Changi was the busiest international air route in 2023, according to a flight data company.

It tops an OAG ranking – illustrated on a world map – created by measuring the routes with the greatest number of scheduled airline seats in either direction.

Last year, there were 4,891,952 seats available on flights from Kuala Lumpur to Singapore Changi, ahead of Cairo to Jeddah, which came second in the list with 4,795,712 seats. Hong Kong came in third place to Taipei with 4,568,280 seats.

London Heathrow to JFK, meanwhile, was in eighth place, with 3,878,590 seats.

The busiest domestic route in 2023 was Jeju to Seoul (13,728,786), and the busiest US domestic route was Honolulu to Kahului (3,612,212).

The above map shows the busiest international flight routes of 2023, according to OAG, which calculated the ranking based on the number of scheduled aircraft seats

THE BUSIEST FLIGHT ROUTES OF 2023 – INTERNATIONAL AND DOMESTIC

International

1. Kuala Lumpur – Singapore Changi (4,891,952 seats)

2. Cairo – Jeddah (4,795,712)

3. Hong Kong – Taipei (4,568,280)

4. Seoul Incheon – Osaka Kansai (4,218,484)

5. Seoul Incheon – Tokyo Narita (4,155,418)

6. Dubai – Riyadh (3,990,076)

7. Jakarta – Singapore Changi (3,910,502)

8. New York JFK – London Heathrow (3,878,590)

9. Bangkok – Singapore Changi (3,478,474)

10. Bangkok – Seoul Incheon (3,362,968)

Domestic

1. Jeju International – Seoul Gimpo (13,728,786 seats)

2. Sapporo New Chitose – Tokyo Haneda (11,936,302)

3. Fukuoka – Tokyo Haneda (11,264,229)

4. Hanoi – Ho Chi Minh City (10,883,555)

5. Melbourne-Sydney (9,342,312)

6. Beijing – Shanghai Hongqiao (8,355,225)

7. Tokyo Haneda – Okinawa Naha (7,982,218)

8. Jeddah – Riyadh (7,902,142)

9. Mumbai – Delhi (7,276,430)

10. Jakarta – Denpasar-Bali (7,190,961)

Source: OAG

The rest of the top 10 busiest international routes for 2023 were Seoul Incheon to Osaka Kansai (fourth, 4,218,484); Seoul Incheon to Tokyo Narita (fifth, 4,155,418); Dubai to Riyadh (sixth, 3,990,076); Jakarta to Singapore Changi (seventh, 3,910,502); Bangkok to Singapore Changi (ninth, 3,478,474), and Bangkok to Seoul Incheon (10th, 3,362,968).

Comparing the results to the 2019 rankings, OAG said half of the top 10 busiest international routes in 2019 were not in the top 10.

These were Cairo to Jeddah (second), Seoul Incheon to Osaka Kansai (fourth), Seoul Incheon to Tokyo Narita (fifth), Dubai to Riyadh (sixth) and Bangkok to Incheon (10th).

The busiest domestic route in 2023 was Jeju to Seoul, with 13,728,786 planned seats

New York JFK to London Heathrow ranks eighth (above) as the busiest international flight route, with 3,878,590 seats

Coming in second in the domestic rankings was Hokkaido's Chitose Airport to Tokyo Haneda with 11,936,302 seats.

Fukuoka to Tokyo Haneda followed closely in third place with 11,264,229 seats, with OAG noting: “There is only a six percent capacity difference between second and third places.”

The rest of the top 10 domestic routes included Hanoi to Ho Chi Minh City (fourth, 10,883,555); Melbourne to Sydney (fifth, 9,342,312); Beijing to Shanghai Hongqiao (sixth, 8,355,225); Tokyo Haneda to Okinawa Naha (seventh, 7,982,218); Jeddah to Riyadh (eighth, 7,902,142); Mumbai to Delhi (ninth, 7,276,430), and Jakarta to Denpasar-Bali (10th, 7,190,961).

OAG added that Jakarta to Denpasar is the only route in the top 10 busiest domestic routes that was not in the top 10 in 2019.

Honolulu (above) to Kahului is the US's busiest domestic route with 3,612,212 seats, according to OAG

TOP 10 BUSIEST DOMESTIC FLIGHT ROUTES IN THE US OF 2023

1. Honolulu – Kahului (3,612,212 seats)

2. Atlanta-Orlando (3,515,882)

3. Las Vegas – Los Angeles (3,496,170)

4. New York JFK – Los Angeles (3,241,663)

5. Denver-Las Vegas (3,198,098)

6. Los Angeles – San Francisco (3,130,328)

7. Atlanta-Fort Lauderdale (3,045,220)

8. Denver-Phoenix (3,040,961)

9. Atlanta – New York LaGuardia (2,707,958)

10. Los Angeles – Chicago O'Hare (2,672,269)

Source: OAG

Atlanta to Orlando was the second busiest domestic route in the US with 3,515,882 seats, followed by Las Vegas to Los Angeles in third place (3,496,170).

The top 10 busiest US domestic routes were rounded out by New York JFK to Los Angeles (fourth, 3,241,663); Denver to Las Vegas (fifth, 3,198,098); Los Angeles to San Francisco (sixth, 3,130,328); Atlanta to Fort Lauderdale (seventh, 3,045,220); Denver to Phoenix (eighth, 3,040,961); Atlanta to New York La Guardia (ninth, 2,707,958), and Los Angeles to Chicago O'Hare (10th, 2,672,269).

OAG reveals that there were three routes in the top 10 busiest domestic routes in the US that were not in the top 10 in 2019, including Honolulu to Kahului (first), Denver to Las Vegas (fifth) and Denver to Phoenix (eighth).

Los Angeles to San Francisco was the busiest U.S. route in 2019, but fell to sixth place in 2023 with a 33 percent drop in capacity.