Megahubs 2025 is the 10th annual edition of the market's definitive ranking of the top internationally connected airports in the world. From 2015 to today, these airports have shaped how the world connects. OAG’s Chief Analyst, John Grant, takes a look at a decade of growth.

Powered by the industry’s most comprehensive and accurate airline schedules and global flight connections data, OAG’s Megahubs analysis provides essential insights on how flight connectivity evolves and grows across the world’s largest airports. Throughout the past decade, we have closely tracked how these Megahubs have developed, with their networks adapting alongside market trends, airline growth strategies, and the popularity of each destination as a stopover point.

To mark the 10^th anniversary this year, we’ve examined the evolution of this year’s Top 10 Global Megahubs over the last decade - set against a backdrop of a near one-third increase in global capacity, now just over six billion seats a year.

Relative to each other, the 2025 Top 10 would have ranked quite differently in 2015, with some of the rankings changing quite considerably for some airports. This reflects the shifting balance of power across the global aviation industry.

Despite the increasing levels of competition, a 24% increase in destinations served underpins London Heathrow (LHR)'s ranking as the best-connected airport over the last decade, and it retains its number one position this year. There are challengers though, and Amsterdam (AMS) has increased its position from 7^th up to 3^rd most connected hub globally. The other major European hubs in Frankfurt (FRA) and Paris (CDG) have both seen their positions drop - in part as a consequence of reductions in domestic connectivity and a shift to alternate modes of transport. Paris (CDG) is now in 10^th place, from 6^th a decade ago and Frankfurt (FRA) is down from 3^rd to 4^th.

At the same time, Megahubs such as Istanbul (IST), Incheon (ICN) and Kuala Lumpur (KUL) have also improved their rankings as their networks and connectivity continues to develop in line with the growth markets that they serve.

• Istanbul (IST) moves into 2^nd place globally from 4^th just 10 years ago, with a 24% increase in the destinations served.
• Kuala Lumpur (KUL) moves up to 4^th from 5^th, with a similar increase in destinations served (22%).
  
• Incheon (ICN) stands out as a big mover, moving up 6^th from 10^th, with a huge increase in potential connections of 58% on the busiest day of the year.

Amongst the US airports in the Top 10, Atlanta (ATL) has held its position, relative to the others, in 8^th place. Chicago O’Hare (ORD), meanwhile, has slipped from what would have been second place in 2015 to 7^th in 2025, as others have seen a bigger increase in connections relative to the destinations served.

While many of the changes are subtle, a glance back just ten years shows us how the world is changing and perhaps point to how those Megahubs will evolve in the next decade.