Indonesia's capital Jakarta has overtaken Tokyo to become the world's largest city, with a population of 42 million and rising, according to UN researchers. Tokyo had held the title for 25 years, but its population growth has slowed significantly.
Jakarta's population dwarfs London's 9.8 million residents. The city boasts Transjakarta, the world's longest bus rapid transit system at 251 km, serving over a million passengers daily. Its metro and light rail systems are still developing.
However, Jakarta faces major challenges due to its size, including chronic traffic congestion, pollution, and flooding. In 2019, the government announced plans to move the capital to Nusantara, a purpose-built city on Borneo, but the project is behind schedule and struggling to attract investment.
Tokyo, meanwhile, is experiencing population decline. Government data shows the number of Japanese nationals fell by over 900,000 in 2024. The city's peak population was 12.7 million in 2009, with a gradual decline since. Despite subsidies and paternity leave incentives, births hit a record low of 687,689 in 2024.
Globally, urbanisation is accelerating. Cities now house 45% of the world's 8.2 billion people, and by 2050, two-thirds of population growth is expected in cities. Asia is home to over half of the world's megacities, and the number of such cities is projected to reach 37 by 2050.
