| '''Summary'''
|Specifies the interface language. Currently, seven languages are available: 'English', 'German', 'French', 'Dutch', 'Italian', 'Japanese', and 'Vietnamese'.
|}
===LANGKEY===
{| width='100%'
|- valign="top"
| width='120' | '''Signature'''
|{{Code|LANGKEY [boolean]}}
|- valign="top"
| '''Default'''
|{{Code|false}}
|- valign="top"
| '''Summary'''
|Prefixes all texts with the internal language keys. This option is helpful if BaseX is translated into another language, and if you want to see where particular texts are displayed.
|}