What language is the primary official language of Indonesia?

Indonesian is the primary official language of Indonesia.

Known locally as Bahasa Indonesia, Indonesian serves as the country’s national language and a common means of communication across its extraordinarily diverse population. Indonesia has hundreds of living languages, including Javanese, Sundanese, Madurese, and Balinese, so a shared national language is especially important for education, administration, media, and public life.

Indonesian developed from Malay, a major trading and literary language of the region. The Youth Pledge of 1928 promoted Bahasa Indonesia as a unifying national language during the independence movement. Indonesia proclaimed independence in 1945, and Indonesian became central to the new republic.

Indonesian and Malay remain closely related, but their standardized forms have developed separately in Indonesia and Malaysia. Indonesian also contains many loanwords from Javanese, Dutch, Arabic, Sanskrit, Portuguese, and English.