Jakarta (Indonesia) has overtaken Tokyo (Japan) as the most populous city in the world, according to the latest report from the United Nations (UN). The 2025 edition of its World Urbanisation Prospects estimates Jakarta’s population at nearly 42 million people, placing it ahead of Dhaka (around 37 million) and Tokyo (about 33 million).
The change stems not only from population growth but also from a revised UN methodology for defining “urban areas,” standardizing criteria across countries to produce more comparable global rankings.
The scale of urbanisation: from handful to dozens of megacities
According to the UN, nearly 45 % of the planet’s 8.2 billion people now live in cities — up from just 20 % in 1950. ООН+1 The number of “megacities” — urban areas with 10 million or more inhabitants — has soared from 8 in 1975 to 33 in 2025.
Importantly, nine of the world’s ten most populated megacities are now in Asia, highlighting the continent’s central role in the future of urban growth.
What this ranking shift says about Jakarta — and its challenges
Jakarta’s leap to the top reflects decades of rapid expansion. The metropolitan region (often referred to as “Greater Jakarta” or Jabodetabek) now sprawls across vast suburban zones, absorbing migrants from across Indonesia in search of jobs and opportunity.
But with size comes strain: the city grapples with notorious traffic congestion, pollution, chronic flooding risk and infrastructure under pressure — problems exacerbated by high population density. In fact, part of the rationale behind Indonesia’s earlier decision to relocate its administrative capital from Jakarta to a newly built city on Borneo — Nusantara — stems from the unsustainable growth of the capital.
Bigger picture: urbanisation reshaping the globe
The rise of megacities like Jakarta reflects broader demographic trends: migration from rural areas to urban centres, the search for employment and better living standards, and shifting birth rates.
Such massive urban concentrations bring both opportunities and challenges. On one hand: economic growth, cultural dynamism, and innovation. On the other: environmental stress, inequality, housing shortages, and the burden on public services. As the UN notes, how urbanisation is managed — in terms of planning, infrastructure, sustainability and social equity — will define the well-being of hundreds of millions.
What’s next — projections and questions for the decades ahead
The report suggests that by 2050, two-thirds of global population growth will be urban. Meanwhile, other rapidly expanding cities — especially in Asia and Africa — could challenge today’s giants.
For Jakarta specifically: maintaining livability amid ballooning scale will require urgent investment in infrastructure — sustainable housing, transport, flood protections, green space, and equitable access to services. The question is whether Indonesia can keep pace with the scale of the challenge before the city’s growth becomes overtaken by its own problems.
