UTF-32
UTF-32 in character encoding
UTF-32 uses a fixed 4 bytes (32 bits) per character, making it the simplest Unicode encoding: code point U+0041 (letter A) is stored as 0x00000041, and every other character is equally straightforward to index.
The tradeoff is size. ASCII text in UTF-32 is 4x larger than in UTF-8. An English text file of 1 MB in UTF-8 would be 4 MB in UTF-32 with no additional characters. For this reason, UTF-32 is rarely used for storage or transmission. Its niche is internal processing where constant-time character indexing matters - Python 3's string implementation uses UTF-32 internally for strings containing characters above U+FFFF. Compare with UTF-16 (variable 2 or 4 bytes) and UTF-8 (variable 1-4 bytes).
The tradeoff is size. ASCII text in UTF-32 is 4x larger than in UTF-8. An English text file of 1 MB in UTF-8 would be 4 MB in UTF-32 with no additional characters. For this reason, UTF-32 is rarely used for storage or transmission. Its niche is internal processing where constant-time character indexing matters - Python 3's string implementation uses UTF-32 internally for strings containing characters above U+FFFF. Compare with UTF-16 (variable 2 or 4 bytes) and UTF-8 (variable 1-4 bytes).