Karachi (Urdu: کراچی; Sindhi: ڪراچي; ALA-LC: Karācī, IPA: [kəˈraːtʃi] (listen)) is the capital of the Pakistani province of Sindh. It is the largest city in Pakistan and the twelfth largest city in the world. Ranked as a beta-global city, the city is Pakistan's premier industrial and financial centre, with an estimated GDP of $114 billion (PPP) as of 2014. Karachi is Pakistan's most cosmopolitan city, linguistically, ethnically, and religiously diverse, as well as one of Pakistan's most secular and socially liberal cities. With its location on the Arabian Sea, Karachi serves as a transport hub, and is home to Pakistan's two largest seaports, the Port of Karachi and Port Bin Qasim, as well as Pakistan's busiest airport, Jinnah International Airport.
Though the Karachi region has been inhabited for millennia, the city was founded as the fortified village of Kolachi in 1729. The settlement drastically increased in importance with the arrival of British East India Company in the mid 19th century. The British embarked on major works to transform the city into a major seaport, and connected it with their extensive railway network. By the time of the Partition of British India, the city was the largest in Sindh with an estimated population of 400,000. Following the independence of Pakistan, the city's population increased dramatically with the arrival of hundreds of thousands of Muslim refugees from India. The city experienced rapid economic growth following independence, attracting migrants from throughout Pakistan and South Asia. According to the 2017 census, Karachi's total population was 16,051,521 and its urban population was 14.9 million. Karachi is one of the world's fastest growing cities, and has communities representing almost every ethnic group in Pakistan. Karachi is home to more than two million Bangladeshi immigrants, a million Afghan refugees, and up to 400,000 Rohingyas from Myanmar.Karachi is now Pakistan's premier industrial and financial centre. The city has a formal economy estimated to be worth $114 billion as of 2014 which is the largest in Pakistan. Karachi collects more than a third of Pakistan's tax revenue, and generates approximately 20% of Pakistan's GDP. Approximately 30% of Pakistani industrial output is from Karachi, while Karachi's ports handle approximately 95% of Pakistan's foreign trade. Approximately 90% of the multinational corporations operating in Pakistan are headquartered in Karachi. Karachi is considered to be Pakistan's fashion capital, and has hosted the annual Karachi Fashion Week since 2009.Known as the "City of Lights" in the 1960s and 1970s for its vibrant nightlife, Karachi was beset by sharp ethnic, sectarian, and political conflict in the 1980s with the arrival of weaponry during the Soviet–Afghan War. The city had become well known for its high rates of violent crime, but recorded crimes sharply decreased following a crackdown operation against criminals, the MQM political party, and Islamist militants initiated in 2013 by the Pakistan Rangers. As a result of the operation, Karachi went from being ranked the world's 6th most dangerous city for crime in 2014, to 105th by early 2021.