The number of languages of Indonesia is 742. Of those, 737 are living languages, 2 are second language without mother-tongue speakers, and 3 are extinct. Most belong to the Austronesian language family, with a few Papuan languages also spoken. The official language is Indonesian (locally known as Bahasa Indonesia), a modified version of Malay, which is used in commerce, administration, education and the media, but most Indonesians speak local languages, such as Javanese, as their first language.

Like most writing systems in human history, Indonesia's are not rendered in invented systems, but devised by speakers of Sanskrit, Arabic, and Latin. Malay, for example, has a long history as a written language and has been rendered in Indic, Arabic, and Roman writing systems. Javanese has been written in the Nagarai and Pallava writing systems of India, in a modified Arabic system called pegon that incorporates Javanese sounds, and in the Roman alphabet. Chinese characters have never been used to express Indonesian languages, although Indonesian place-names, personal names, and names of trade goods appear in reports and histories written for China's imperial courts.

Languages spoken in Indonesia