UTF32LE

UTF-32 Little‑Endian (UTF32LE) is a Unicode character encoding that represents each character with a 32‑bit code unit, arranged in little‑endian byte order (least significant byte first). Each Unicode code point from the Basic Multilingual Plane and supplementary planes is encoded in a single, fixed‑length unit, which eliminates the need for surrogate pairs used in UTF‑16. Because the size of each code unit is constant, indexing and random access to characters are straightforward, making UTF32LE useful in situations where performance and simplicity of access outweigh memory efficiency.

UTF32LE does not require a byte‑order mark (BOM) to indicate endianness; the file format itself implies little‑endian byte order. However, it is common practice for interoperability to prepend a BOM (0xFF 0xFE 0x00 0x00) to explicitly signify UTF‑32 LE, especially in Windows environments. Some software accepts files without a BOM but assumes the system’s native endianness.

Memory overhead is a drawback: UTF32LE uses four bytes per character, quadrupling the storage size compared to UTF‑8 for typical English text. Consequently, it is seldom employed for general file formats or network communication, where UTF‑8 or UTF‑16 are preferred. Nevertheless, UTF32LE is found in legacy Windows APIs, certain database fields, and internal data structures where simple indexing is valued over compactness.