UTF-16 is a 16-bit text encoding capable of encoding a much wider range of characters than ASCII. UTF stands for Unicode Transformation Format.

The minimum size for each character is 16 bits, twice as large as the minimum size for UTF-8, although the maximum size to encode a character is the same for both (4 bytes).

There are two principal varieties of UTF-16, little-endian and big-endian, often abbreviated to UTF-16 LE and UTF-16 BE. The difference between the two varieties is the order in which the bytes are stored in each 16 bit word. The little-endian version stores the least-significant byte first, and the big-endian version stores the most-significant byte first.