Jakarta. The United Nations has named Jakarta the world’s most densely populated metropolitan area, projecting its population at 42 million people and overtaking Tokyo for the first time in decades.

The Jakarta Provincial Government on Thursday clarified how the UN arrived at the figure, noting that it reflects daily urban activity rather than the official resident count.

The projection comes from the UN’s World Urbanization Prospects 2025, released this week, which lists Jakarta at the top of the global density ranking. For years, Tokyo held the title, but demographic shifts and new measurement methods have reshaped the list.

Chico Hakim, Special Staff to the Jakarta Governor for Public Communication, said the UN’s 42 million figure is based on the degree of urbanization concept. The metric counts people who use the metropolitan area daily, not those officially registered as residents.

Under Indonesia’s official population definition, however, the picture looks very different. Using the country-based method applied in the 2018 revision of World Urbanization Prospects, Jakarta’s population in 2025 is estimated at about 11 million, placing it 30th among the world’s densest cities.

Chico said the UN number reflects the reality that Jakarta functions as the economic, educational, and administrative center for millions who commute daily from surrounding Greater Jakarta, consisting of Bogor, Depok, Tangerang, and Bekasi.

Every day, millions travel into Jakarta for work, school, health services, business, and government administration. This enormous mobility, Chico said, creates the impression of a megacity far larger than its official population.

“This daily movement is what makes Jakarta feel much denser than its registered population suggests,” he said.

The UN Department of Economic and Social Affairs ranked Jakarta first on its latest list of densely populated metropolitan regions. Dhaka, Bangladesh's capital, follows with nearly 40 million people, while Tokyo,long the world’s most populated metro area, has dropped to third with around 33 million amid Japan’s slowing population growth and deepening demographic challenges.