Demographics

The 2010 census recorded Indonesia's population as 237.6 million, the fourth largest in the world, with high population growth at 1.9%. Java is the world's most populous island, where 58% of the country's population lives. The population density is 138 people per km2 (357 per sq mi), ranking 88th in the world, although Java has a population density of 1,067 people per km2 (2,435 per sq mi). In 1961, the first post-colonial census recorded a total of 97 million people. It is expected to grow to around 295 million by 2030 and 321 million by 2050. The country currently possesses a relatively young population, with a median age of 30.2 years (2017 estimate).

The spread of the population is uneven throughout the archipelago with a varying habitat and level of development, ranging from the megacity of Jakarta to uncontacted tribes in Papua. As of 2017, about 54.7% of the population lives in urban areas. Jakarta is the country's primate city and the second-most populous urban area in the world with over 34 million residents. About 8 million Indonesians live overseas; most settled in Malaysia, the Netherlands, Saudi Arabia, the United Arab Emirates, Hong Kong, Singapore, the United States, and Australia.

v t e Largest cities in Indonesia 2015 inter-census survey
	Rank	Name	Province	Pop.	Rank	Name	Province	Pop.
Jakarta Surabaya	1	Jakarta	Jakarta	10,154,134	11	Makassar	South Sulawesi	1,447,677	Bekasi Bandung
	2	Surabaya	East Java	2,847,480	12	Batam	Riau Islands	1,184,978
	3	Bekasi	West Java	2,708,721	13	Bogor	West Java	1,046,579
	4	Bandung	West Java	2,480,615	14	Pekanbaru	Riau	1,035,834
	5	Medan	North Sumatra	2,209,139	15	Bandar Lampung	Lampung	977,686
	6	Depok	West Java	2,099,989	16	Padang	West Sumatra	901,305
	7	Tangerang	Banten	2,043,213	17	Denpasar	Bali	879,098
	8	Semarang	Central Java	1,698,777	18	Malang	East Java	850,904
	9	Palembang	South Sumatra	1,578,582	19	Samarinda	East Kalimantan	811,314
	10	South Tangerang	Banten	1,538,970	20	Banjarmasin	South Kalimantan	674,739

Ethnic groups and languages

Indonesia is an ethnically diverse country, with around 600 distinct native ethnic groups. Most Indonesians are descended from Austronesian peoples whose languages had origins in Proto-Austronesian, which possibly originated in what is now Taiwan. Another major grouping is the Melanesians, who inhabit eastern Indonesia (the Maluku Islands and Western New Guinea).

The Javanese are the largest ethnic group, constituting 40.2% of the population, and are politically dominant. They are predominantly located in the central to eastern parts of Java and also sizable numbers in most provinces. The Sundanese, Malay, Batak, Madurese, Minangkabau and Buginese are the next largest groups in the country.b A sense of Indonesian nationhood exists alongside strong regional identities.

The country's official language is Indonesian, a variant of Malay based on its prestige dialect, which for centuries had been the lingua franca of the archipelago. It was promoted by nationalists in the 1920s and achieved official status under the name Bahasa Indonesia in 1945. As a result of centuries-long contact with other languages, it is rich in local and foreign influences, including from Javanese, Sundanese, Minangkabau, Hindi, Sanskrit, Chinese, Arabic, Dutch, Portuguese and English. Nearly every Indonesian speaks the language due to its widespread use in education, academics, communications, business, politics, and mass media. Most Indonesians also speak at least one of more than 700 local languages, often as their first language. Most belong to the Austronesian language family, while there are over 270 Papuan languages spoken in eastern Indonesia. Of these, Javanese is the most widely spoken.

In 1930, Dutch and other Europeans (Totok), Eurasians, and derivative people like the Indos, numbered 240,000 or 0.4% of the total population. Historically, they constituted only a tiny fraction of the native population and continue to do so today. Despite the Dutch presence for almost 350 years, the Dutch language never had a substantial number of speakers or official status. The small minorities that can speak it or Dutch-based creole languages fluently are the aforementioned ethnic groups and descendants of Dutch colonisers. Today, there is some degree of fluency by either educated members of the oldest generation or legal professionals, as specific law codes are still only available in Dutch.

Religion

While the constitution stipulates religious freedom, the government officially recognises only six religions: Islam, Protestantism, Roman Catholicism, Hinduism, Buddhism, and Confucianism; with indigenous religions only partly acknowledged. Indonesia is the world's most populous Muslim-majority country with 227 million adherents in 2017, with the majority being Sunnis (99%). The Shias and Ahmadis respectively constitute 1% (1–3 million) and 0.2% (200,000–400,000) of the Muslim population. Almost 11% of Indonesians are Christians, while the rest are Hindus, Buddhists, and others. Most Hindus are Balinese, and most Buddhists are Chinese Indonesians.

The natives of the Indonesian archipelago originally practised indigenous animism and dynamism, beliefs that are common to Austronesian people. They worshipped and revered ancestral spirit, and believed that supernatural spirits (hyang) might inhabit certain places such as large trees, stones, forests, mountains, or sacred sites. Examples of Indonesian native belief systems include the Sundanese Sunda Wiwitan, Dayak's Kaharingan, and the Javanese Kejawèn. They have had a significant impact on how other faiths are practised, evidenced by a large proportion of people—such as the Javanese abangan, Balinese Hindus, and Dayak Christians—practising a less orthodox, syncretic form of their religion.

Hindu influences reached the archipelago as early as the first century CE. The Sundanese Kingdom of Salakanagara in western Java around 130 was the first historically recorded Indianised kingdom in the archipelago. Buddhism arrived around the 6th century, and its history in Indonesia is closely related to that of Hinduism, as some empires based on Buddhism had its roots around the same period. The archipelago has witnessed the rise and fall of powerful and influential Hindu and Buddhist empires such as Majapahit, Sailendra, Srivijaya, and Mataram. Though no longer a majority, Hinduism and Buddhism remain defining influences in Indonesian culture.

Islam was introduced by Sunni traders of the Shafi'i fiqh, as well as Sufi traders from the Indian subcontinent and southern Arabian peninsula as early as the 8th century CE. For the most part, Islam overlaid and mixed with existing cultural and religious influences that resulted in a distinct form of Islam. Trade, missionary works such as by the Wali Sanga and Chinese explorer Zheng He, and military campaigns by several sultanates helped accelerate the spread of the religion. By the end of the 16th century, Islam had supplanted Hinduism and Buddhism as the dominant religion of Java and Sumatra.

Catholicism was brought by Portuguese traders and missionaries such as Jesuit Francis Xavier, who visited and baptised several thousand locals. Its spread faced difficulty due to the VOC policy of banning the religion and the Dutch hostility due to the Eighty Years' War against Catholic Spain's rule. Protestantism is mostly a result of Calvinist and Lutheran missionary efforts during the Dutch colonial era. Although they are the most common branch, there is a multitude of other denominations elsewhere in the country.

There was a sizable Jewish presence in the archipelago until 1945, mostly Dutch and some Baghdadi Jews. Since most have left after Indonesia proclaimed independence, Judaism was never accorded official status, and only a tiny number of Jews remain today, mostly in Jakarta and Surabaya. At the national and local level, Indonesia's political leadership and civil society groups have played a crucial role in interfaith relations, both positively and negatively. The invocation of the first principle of Indonesia's philosophical foundation, Pancasila (the belief in the one and only God) often serves as a reminder of religious tolerance, though instances of intolerance have occurred. An overwhelming majority of Indonesians consider religion to be essential, and its role is present in almost all aspects of society, including politics, education, marriage, and public holidays.

Education and health

Education is compulsory for 12 years. Parents can choose between state-run, non-sectarian schools or private or semi-private religious (usually Islamic) schools, supervised by the ministries of Education and Religion, respectively. Private international schools that do not follow the national curriculum are also available. The enrolment rate is 93% for primary education, 79% for secondary education, and 36% for tertiary education (2018). The literacy rate is 96% (2018), and the government spends about 3.6% of GDP (2015) on education. In 2018, there were more than 4,500 higher educational institutions in Indonesia. The top universities are the Java-based University of Indonesia, Bandung Institute of Technology and Gadjah Mada University. Andalas University is pioneering the establishment of a leading university outside of Java.

Government expenditure on healthcare is about 3.3% of GDP in 2016. As part of an attempt to achieve universal health care, the government launched the National Health Insurance (Jaminan Kesehatan Nasional, JKN) in 2014 that provides healthcare to citizens. They include coverage for a range of services from the public and also private firms that have opted to join the scheme. In recent decades, there have been remarkable improvements such as rising life expectancy (from 62.3 years in 1990 to 71.7 years in 2019) and declining child mortality (from 84 deaths per 1,000 births in 1990 to 25.4 deaths in 2017). Nevertheless, Indonesia continues to face challenges that include maternal and child health, low air quality, malnutrition, high rate of smoking, and infectious diseases.

Issues

Nearly 80% of Indonesia's population lives in the western parts of the archipelago, but they are growing at a slower pace than the rest of the country. This situation creates a gap in wealth, unemployment rate, and health between densely populated islands and economic centres (such as Sumatra and Java) and sparsely populated, disadvantaged areas (such as Maluku and Papua). Numerous cases of racism and discrimination, especially against Chinese Indonesians and Papuans, have been well documented. LGBT issues in Indonesia has been relatively obscure. However, in the 2010s (especially after 2016), a wave of anti-LGBT rhetoric has surged rapidly, putting LGBT Indonesians into frequent subject of intimidation, discrimination, and even violence.