Tokyo has slipped from its decades-long position as the world’s largest megacity, falling to third place as Jakarta and Dhaka surge ahead, according to a new United Nations report.

The findings show Jakarta, now approaching 42 million residents, has become the world’s most populous urban centre in 2025.

Dhaka follows with nearly 37 million people and is projected to overtake Jakarta by 2050, reaching an estimated 52.1 million.

The report highlights a dramatic shift in global urbanisation.
The number of megacities — those with populations of 10 million and above — has jumped from eight in 1975 to 33 in 2025.
The majority of them are located in Asia.

In contrast, only 20% of the world’s population lived in cities in 1950.

Tokyo, long the world’s most populous metropolis with 33.4 million residents, has been outpaced as Jakarta and Dhaka expanded at rates five to seven times faster since 2000.

The Japanese capital is expected to slide further down the rankings to seventh place by mid-century, overtaken by cities including Shanghai and New Delhi.

Despite the global rise, Europe is not expected to add any new megacities by 2050.

London, Istanbul and Moscow will remain the continent’s only cities above the 10-million mark.

London’s population is projected to grow by around 1.5 million, keeping it the world’s 33rd largest urban centre—and the smallest megacity in Europe.

The report also notes that most cities worldwide remain relatively small: 96% have fewer than 1 million inhabitants, and 81% have populations below 250,000.

According to the report, around 45% of people now live in cities, with 36% in towns and 19% in rural areas.