Jakarta, Tokyo, Dhaka: UN places Asia in megacity leadership 2025

(JAKARTA, INDONESIA) Indonesia’s capital Jakarta has been named the world’s largest city, overtaking Tokyo and marking a major shift in global urban power, according to a new United Nations report released on November 18, 2025. The World Urbanization Prospects 2025 report, published by the UN Department of Economic and Social Affairs (UN DESA), places Jakarta at the top of the global rankings with a population of nearly 42 million people.

Bangladesh’s capital Dhaka now sits in second place with almost 40 million residents, while Tokyo, long seen as the archetypal megacity, has slipped to third with about 33 million people. The reshuffling of the top three confirms a trend that has been building for years: the world’s biggest cities are increasingly concentrated in Asia, and their populations are still growing.

UN DESA defines these giant urban centres as megacities, meaning urban areas with 10 million or more inhabitants. The new report underlines just how dominant Asia has become in this category. Nine of the world’s top 10 megacities are now in Asia, with only Cairo breaking the regional pattern. Other cities in the top tier, alongside Jakarta, Dhaka and Tokyo, include New Delhi, Shanghai, Guangzhou, Manila, Kolkata, Seoul and Cairo.

The figures show how rapidly the urban map has been redrawn over the past half-century. In 1975, there were just 8 megacities around the globe. By 2025, that number has more than quadrupled to 33, with over half of them—19 in total—located in Asia. The report also projects that the number of megacities will continue to rise, reaching 37 by 2050 as more people move into dense urban areas.

Jakarta’s leap to the top reflects what the report describes as continued urban migration and population growth in the Indonesian capital. The city’s nearly 42 million people make it not only the most populous in the world today, but also a symbol of the broader shift of economic and demographic weight towards Asian cities. While Tokyo’s population has remained relatively stable, Jakarta has continued to expand, drawing people from across Indonesia’s vast archipelago into its dense metropolitan region.

Dhaka’s rise to second place is even more closely tied to migration patterns. The UN report attributes the city’s surge to rural-to-urban migration, driven in part by climate change impacts such as flooding and rising sea levels. For Bangladesh, one of the countries most exposed to climate-related risks, this movement from vulnerable rural and coastal areas into the capital has helped push Dhaka’s population to almost 40 million. The report goes further, projecting that Dhaka is on track to become the world’s largest city by 2050, overtaking both Jakarta and Tokyo.

Tokyo’s fall to third in the ranking does not reflect a sharp decline so much as the relative slowing of its growth compared with Jakarta and Dhaka. With about 33 million people, the Japanese capital remains one of the largest and most densely populated cities on Earth. But the UN figures suggest that its era as the world’s largest metropolitan area has ended, replaced by faster-growing urban regions in Southeast and South Asia.

The clustering of Jakarta, Dhaka and Tokyo among the top three underscores how Asia now anchors the world’s urban future. From New Delhi and Shanghai to Guangzhou, Manila, Kolkata and Seoul, Asian megacities dominate the upper end of the UN’s global rankings. Cairo, the only non-Asian city in the top 10, stands out as an exception on a list otherwise crowded with Asian urban giants.

The report also zooms out to the global picture of urbanization. It notes that cities now house 45% of the world’s population of 8.2 billion people. That means more than three and a half billion people live in urban areas, and the trend is still upward. By 2050, two-thirds of global population growth is expected to occur in cities, cementing their role as the main places where people live, work and move in search of opportunity.

What makes these new rankings particularly striking is the way they are measured. All of the data and projections in the World Urbanization Prospects 2025 report are based on a new UN methodology that looks beyond traditional administrative boundaries. Instead of counting only residents within city limits, the UN uses what it calls a “contiguous agglomeration” approach to define cities. Under this method, cities are identified using grid cells with at least 1,500 inhabitants per square kilometer and a total population of at least 50,000.

This shift to “contiguous agglomeration” helps capture the true scale of modern urban regions, where people often live and work across multiple municipalities and suburbs that blend into each other. For Jakarta, the methodology takes in the sprawling built-up area that extends far beyond the historic core, helping to explain its climb to nearly 42 million people. The same logic applies to Dhaka and Tokyo, where dense networks of housing, industry and infrastructure spill across official borders.

By applying a consistent measure based on population density and continuous built-up areas, UN DESA argues that it can compare cities such as Jakarta, Tokyo and Dhaka more accurately. It also means that the rankings reflect where people actually live and move each day, rather than relying on older administrative definitions that may no longer match the reality on the ground. The methodology is part of a wider effort by the UN to track how urbanization is reshaping economies, societies and the environment, work that sits within the population analysis carried out by UN DESA’s Population Division.

For Jakarta, the new ranking confirms the city’s status as a hub not just for Indonesia but for the region, tying it more closely in comparison with other Asian capitals like Tokyo and Dhaka that sit near the top of the UN list. The sheer number of people counted in Jakarta’s contiguous urban area signals the scale of the city’s housing, transport and basic services, which must support tens of millions of residents and commuters across its vast metropolitan footprint.

Dhaka’s position and its projected rise to first place by 2050 highlight different pressures. The report links much of the city’s growth to rural-to-urban migration, a pattern that is shaped by climate change impacts such as flooding and rising sea levels. That framing places Dhaka at the heart of a global story in which climate pressures push people away from rural livelihoods and into rapidly growing cities, even as those cities themselves face exposure to extreme weather and environmental stress.

Tokyo’s move to third, meanwhile, reflects how even the world’s best-known megacities can be overtaken when other urban regions grow faster. With a relatively stable population of about 33 million, Tokyo remains a vast and complex metropolis. But Jakarta and Dhaka, with their faster pace of urban migration and population growth, now sit ahead in the UN’s global tables.

The expansion of Asia’s megacities—from Jakarta in Southeast Asia to Tokyo in East Asia and Dhaka in South Asia—also mirrors wider demographic trends, with large populations and ongoing urban migration converging in dense, sprawling conurbations. The UN’s count of 33 megacities in 2025, rising from just 8 in 1975, signals how exceptional these giant urban centres have become in size, while their concentration in Asia underlines the region’s central role in shaping the urban century.

As the UN report makes clear, these changes are not just about rankings. With 45% of the world’s 8.2 billion people already living in cities and two-thirds of future population growth expected to be urban, megacities like Jakarta, Tokyo and Dhaka sit at the forefront of social, economic and environmental change. By tracking their growth using the “contiguous agglomeration” method and projecting how cities like Dhaka may overtake Jakarta by 2050, the World Urbanization Prospects 2025 report offers a snapshot of a world becoming more urban, more Asian and more concentrated in vast city regions than ever before.