Under the UN's newly harmonised 2025 methodology, Jakarta has overtaken Tokyo as the world's most populous urban agglomeration — and nine of the top ten are in Asia.
Quick answer: 1. Jakarta, 2. Dhaka, 3. Tokyo, 4. Delhi, 5. Shanghai, 6. Guangzhou, 7. Cairo, 8. Manila, 9. Kolkata, 10. Seoul.
This is a ranking of the world's ten largest cities by urban agglomeration population, using the United Nations' World Urbanization Prospects 2025. The 2025 revision is a big deal: the UN switched from stitching together inconsistent national definitions to a single satellite-measured method, and the new numbers reshuffle the top of the list — Tokyo, long the reigning champion, drops to third behind Jakarta and Dhaka. If you want to know which cities actually pack in the most people (not just which sit inside the biggest administrative lines on a map), this is the list. It's built for anyone comparing megacities on a like-for-like basis: the population counted here is the contiguous built-up area, not the city limits.
Greater Jakarta (Jabodetabek) is now the world's most populous urban agglomeration under the UN's 2025 harmonised methodology, dethroning Tokyo. Its built-up sprawl reaches far beyond the city proper and it is one of the fastest-growing megacities on Earth.
Bangladesh's capital is the second-largest agglomeration in 2025 and the fastest-growing of the group. It is on track to overtake Jakarta by mid-century and, alongside it, be among the first urban areas ever to top 50 million people.
For decades the undisputed largest city on the planet, Tokyo slips to third under the 2025 method as its population declines and faster-growing Asian megacities close the gap. The UN projects it to fall as far as seventh by 2050.
India's capital region ranks fourth and has grown faster in absolute terms than any other top-10 city, adding 12.3 million residents since 2000. It is the largest of India's three entries in the ranking.
China's largest urban agglomeration and its foremost financial and port city ranks fifth. Its growth has been powered by decades of coastal urbanisation.
Guangzhou is the core of the Pearl River Delta, the world's largest contiguous urban region, and ranks sixth. The surrounding megaregion in southern China blurs the line between several once-separate cities.
Cairo is the largest urban agglomeration in both Africa and the Arab world, and the only city in the top 10 outside Asia. It ranks seventh globally.
The Metro Manila region ranks eighth and is one of the most densely populated urban cores on Earth, cramming its people into a comparatively small footprint on the shores of Manila Bay.
India's third entry in the top 10 ranks ninth. It is tied with Seoul at 22.5 million people, with the UN placing it just ahead in the published order.
The Seoul Capital Area rounds out the top 10, tied with Kolkata at 22.5 million and concentrating roughly half of South Korea's entire population in a single agglomeration.
| # | Name | Country | Continent | Growth 2000-2025 |
|---|---|---|---|---|
| 1 | Jakarta | Indonesia | Asia | One of the fastest-growing megacities; projected to exceed 50 million by 2050 |
| 2 | Dhaka | Bangladesh | Asia | Fastest-growing of the top cities; projected to become the world's largest by 2050 |
| 3 | Tokyo | Japan | Asia | Population declining; projected to fall to 7th place by 2050 |
| 4 | Delhi | India | Asia | Gained 12.3 million residents (2000-2025), the largest absolute increase of the group |
| 5 | Shanghai | China | Asia | Major growth driven by China's coastal urbanization |
| 6 | Guangzhou | China | Asia | Anchors the Pearl River Delta, the world's largest contiguous urban region |
| 7 | Cairo | Egypt | Africa | The only non-Asian city in the top 10 |
| 8 | Manila | Philippines | Asia | Among the world's densest urban cores |
| 9 | Kolkata | India | Asia | One of three Indian cities in the top 10 |
| 10 | Seoul | South Korea | Asia | Home to roughly half of South Korea's population |
Cities are ranked by 2025 urban agglomeration population as reported in the UN Department of Economic and Social Affairs' World Urbanization Prospects 2025. WUP 2025 defines a city not by administrative boundaries but as a contiguous agglomeration of 1 km-square grid cells, each with a minimum density of 1,500 inhabitants per square kilometre and the whole forming a settlement of at least 50,000 people; the built-up extent is measured from satellite data via the Global Human Settlement Layer. Because this counts the continuous urban footprint rather than city limits, figures here (e.g. greater Jakarta / Jabodetabek, Metro Manila, the Seoul Capital Area) differ from city-proper populations. Items are ordered highest population first (rank 1 = most populous); where two cities tie on population (Kolkata and Seoul at 22.5 million), the UN's published ordering is followed. All figures are in millions of people.
Jakarta, Indonesia. Under the UN's World Urbanization Prospects 2025, greater Jakarta (the Jabodetabek agglomeration) has about 41.9 million people, overtaking Tokyo as the world's largest urban agglomeration.
Two reasons. First, the UN's 2025 revision switched to a single satellite-measured definition of a city's built-up area instead of relying on differing national boundaries, which changed how populations are counted. Second, Tokyo's population is actually declining while Asian megacities like Jakarta and Dhaka grow rapidly, so it dropped to third place.
By its physical built-up area, not its administrative limits. A city is a contiguous cluster of 1 km-square grid cells, each with at least 1,500 people per square kilometre, together totalling at least 50,000 residents — measured from satellite data (the Global Human Settlement Layer). That is why the figures here for greater Jakarta, Metro Manila or the Seoul Capital Area are larger than the population of the city proper.
Dhaka, Bangladesh. It is currently the fastest-growing city in the top 10 and the UN projects it to overtake Jakarta by mid-century, with both expected to be among the first agglomerations to exceed 50 million people.