Indonesian is written using the Latin alphabet, and is generally phonetically consistent.

Consonants are represented in a way similar to Italian, although c is always /tʃ/ (like English "ch"), g is always /g/ ("hard") and j represents /dʒ/ as it does in English. In addition, ny represents the palatal nasal /ɲ/, ng is used for the velar nasal /ŋ/ (which can occur word-initially), sy for /ʃ/ (English "sh") and kh for the voiceless velar fricative /x/. Both /e/ and /ə/ are represented with an e. One common source of confusion for foreign readers, particularly when reading place names, is the spelling changes in the language that have occurred since Indonesian independence. Commonly-used changes include:

Old Spelling	New Spelling
oe	u
tj	c
dj	j
j	y
nj	ny
sj	sy
ch	kh

The first of these changes (oe to u) occurred around the time of independence in 1947; all of the others were a part of an officially-mandated spelling reform in 1972. Some of the old spellings, which were more closely derived from the Dutch language, do survive in proper names; for example, the name of a former president of the Indonesia is still sometimes written Soeharto, and the central Java city of Yogyakarta is sometimes written Jogjakarta.