Goodbye to Tokyo: an underrated metropolis ‘sinks’ Japan’s capital and becomes the world’s largest

Jakarta, Indonesia’s bustling capital, has officially overtaken Tokyo in the global ranking of the world’s most populous cities, according to a new United Nations report.

With an estimated population of nearly 42 million residents, Jakarta now sits ahead of both Tokyo and Dhaka, Bangladesh—cities that previously outranked it in the UN’s 2018 classification.

Urbanization on the rise

The UN’s World Urbanization Prospects 2025 report highlights a striking reality: nearly half of the planet’s 8.2 billion people now live in cities. Jakarta’s climb in the rankings is just one example of how urban populations have doubled over the past 75 years.

Asia continues to dominate the list. Nine of the world’s 10 largest cities are located on the continent. The lone exception is Cairo, Egypt, which holds seventh place with 25 million residents.

The world’s 10 most populous cities in 202541.9 million Jakarta (Indonesia) is the world’s most populous city36.6 million Dhaka (Bangladesh) 33.4 million Tokyo (Japan) 30.2 million New Delhi (India)29.6 million Shanghai (China)27.6 million Guangzhou (China)25.6 million Al−Qahirah (Cairo)24.7 million Manila (Philippines)22.5 million Kolkata (India)22.5 million Seoul (South Korea)

Japan faces demographic challenges

For Japan, the news underscores a troubling trend. In 1975, there were only eight “megacities” worldwide—defined as cities with more than 10 million inhabitants. Fast forward to 2025, and that number has jumped to 33 megacities, 19 of them in Asia. By comparison, the United States counts just two: New York City and Los Angeles.

Looking ahead, the UN projects the number of cities worldwide could reach 15,000 by 2050, including smaller urban centers with fewer than 250,000 residents. Among the most dramatic forecasts: Dhaka could become the world’s largest city with 52.1 million residents, while Tokyo may lose as many as 2.7 million people due to Japan’s aging population and demographic decline.

Jakarta’s growing pains

Jakarta’s rapid growth comes with serious challenges. The city is prone to earthquakes and flooding, struggles with high pollution levels, and is literally sinking under its own weight. In 2019, then-President Joko Widodo proposed relocating Indonesia’s capital to Nusantara, a city about 1,200 miles away known for its extraordinary biodiversity.