A new United Nations report has awarded the title of the world’s most populous city to Jakarta, the capital of Indonesia. Overtaking the Japanese capital, Tokyo, for the first time, Jakarta jumped from 33rd place in the last ranking and is now home to an estimated 42 million people. To put that in context, Jakarta’s population is three times the size of New York’s.
Jakarta is now home to three times as many people as New York.
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Tokyo has slipped to third place in the World Urbanization Prospects 2025 report from the population division of the UN’s Depart of Economic and Social Affairs, with an estimated population of 33 million. Second place goes to Bangladeshi capital, Dhaka, with 37 million residents.
The report’s dataset includes the latest estimates of urban and rural populations for 237 countries or areas from 1950 to 2025, with projections until 2050. It also provides estimates of the population size of all cities with 50,000 inhabitants or more by 2025.
This new categorization is not the result of some sudden huge global relocation of people, despite the dramatic change in rankings compared to the UN’s previous 2018 report. It comes from the UN’s new ranking methodology that categorizes rural areas, towns and cities in a more consistent way.
Previous reports were based on data from national statistical authorities according to often wildly different country-specific definitions. The new report fully integrates “new geospatial methods through the harmonized Degree of Urbanization methodology, alongside country-specific definitions.”
Applying this new approach to gridded population and built-up area data allows the new report to, “measure cities, towns and rural areas consistently across countries and over time, while still retaining results based on national definitions for domestic policy use and statistical continuity.”
Today, more people live in cities than in towns and rural areas. Compared to the 1950s when just 20% of the world’s 2.5 billion inhabitants lived in cities, the UN states cities are now home to 45% of the global 8.2 billion population. Projections indicate a continuing trend, with two-thirds of global population growth expected to take place in cities by 2050.
Of these, a growing proportion will be defined as megacities—those with populations of more than 10 million. The number of these massive urban conurbations has already quadrupled from eight in 1975 to 33 in 2025.
Los Angeles is one of two U.S. megacities with a population of more than 10 million.
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Of those 33 megacities, more than half are located in Asia. In the top ten most populous, the Egyptian capital Cairo is the only non-Asian megacity to feature, ranking seventh with a population of 25 million inhabitants. New York (13.9 million) and Los Angeles (12.7 million) are the only two megacities in the U.S. Istanbul (15 million) is the most populous city in Europe, accompanied by London (10.4 million), the least populous megacity to qualify.
“Urbanization is a defining force of our time,” commented Li Junhia, United Nations undersecretary-general for economic and social affairs. “When managed inclusively and strategically, it can unlock transformative pathways for climate action, economic growth, and social equity.
“To achieve balanced territorial development, countries must adopt integrated national policies that align housing, land use, mobility, and public services across urban and rural areas.”
According to the report, collectively, the seven countries of India, Nigeria, Pakistan, Democratic Republic of the Congo, Egypt, Bangladesh and Ethiopia are expected to add more than 500 million city residents between 2025 and 2050. This will account for more than half of the projected 986 million increase in the global number of city dwellers over that period.
Long the world's most populous city, Tokyo's decreasing population means the city is forecast to continue shrinking. (It's still enormous though.)
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The success or failure of urbanization in these key countries will shape global development outcomes. Their ability to manage city growth sustainably will have profound implications not only for their populations but also for global progress toward the Sustainable Development Goals and climate objectives.
Many existing megacities are having a harder time of it. Tokyo is projected to fall in rank from third in 2025 to seventh in 2050, as it shrinks to around 31 million inhabitants. This is reflective of Japan’s nationwide issue with population decline in recent years as the impact of an ageing population affects every part of society.
All of Jakarta's 42 million residents are subject to pollution and natural disaster, putting the megacity's future in doubt.
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Jakarta on the other hand continues to grow, and is a city choked by overcrowding and massive pollution. It is also at the mercy of nature, prone to earthquakes and, in no small part due to the fact that it’s sinking, flooding. The Indonesian government’s solution to the rapidly escalating problem was radical—a relocation of the capital some 1,200 miles to the island of Borneo, one of the world’s most biodiverse regions.
The new capital, Nusantara, on Borneo’s east coast began construction in 2022 and is slated to be finished by 2045 to coincide with Indonesia’s centenary. To date the project has suffered numerous setbacks, however.
To see the report in full with detailed methodology, read the World Urbanization Prospects 2025.