# UTF

Unicode Transformation Format - UTF - is a character [encoding](/glossary/e/encoding) that maps Unicode code points (characters) to code values.

UTF encoding is available in multiple versions. The two most common types are UTF-8 and UTF-16. 

UTF-8 is a variable-length encoding using up to 8-bit code units. It is backward compatible with [ASCII](/glossary/a/ascii). 

UTF-16 is also variable-length using one or two 16-bit code units.