The metropolis with 42m people that just overtook Tokyo to become world’s biggest megacity

A new megacity has taken the top spot with around 42 million people living there (Image: Getty)

The world’s population is constantly growing and expected to peak in 2100. As a result, more and more megacities are appearing across the planet, even in places where just a few decades ago far fewer people lived. 

According to the United Nations, the number of megacities (urban areas with more than 10 million people) has jumped from just eight in 1975 to 33 today, and almost half of the world now lives in cities. But the biggest megacity of all has just changed, with the long-standing leader finally being overtaken.

Tokyo now sits in third place with 33 million people (Image: Getty)

For years, Tokyo was the world’s largest city, but the latest UN figures show it is no longer in first place. 

A new megacity has taken the top spot with around 42 million people living across its wider metropolitan area.

This is according to the UN’s World Urbanisation Prospects 2025 report, which showed how quickly cities are expanding. 

Tokyo now sits in third place with 33 million people, while Dhaka in Bangladesh has moved into second with 40 million. Cairo in Egypt is the only city outside Asia to make the top ten.

Li Junhua, who leads the UN’s Department of Economic and Social Affairs, said the rise of huge cities will shape the rest of the century.

Jakarta is now officially the world's biggest megacity (Image: Getty)

The sheer size of the region brings daily problems for people living there (Image: Getty)

He said: “Urbanisation is a defining force of our time. When managed inclusively and strategically, it can unlock transformative pathways for climate action, economic growth, and social equity.”

He added: “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.”

The city that has now overtaken Tokyo is Jakarta in Indonesia. The UN estimates the area has almost 42 million people. 

The figure includes Jakarta and the surrounding areas of Bogor, Depok, Tangerang, South Tangerang and Bekasi.

Local experts say the ranking is no surprise. Elisa Sutanudjaja, from the Jakarta-based Rujak Centre for Urban Studies, said the UN report “confirmed what urbanists already knew - that Greater Jakarta’s population had exceeded that of Tokyo for years”.

Residents deal with heavy traffic, crowded roads and high levels of pollution (Image: Getty)

However, the sheer size of the region presents daily challenges for the people living there. Residents deal with heavy traffic, crowded roads, regular flooding and high levels of pollution. 

Parts of the city are also sinking, which has increased pressure on the government to find long-term solutions.

In 2019, Indonesia announced plans to move its capital from Jakarta to a new city called Nusantara on the island of Borneo. 

Construction has been slower than anticipated, and the project has struggled to secure investment; however, the government still plans to relocate some offices there in the coming years.

The UN report also showed which places could soon join the global megacity list. 

Kuala Lumpur in Malaysia is expected to pass 10 million residents by 2050, along with Addis Ababa in Ethiopia and Hajipur in India.

By the middle of the century, Dhaka is predicted to become the largest city in the world, while Tokyo is expected to fall further down the rankings.