Unicode Support

The supported file formats for text files and scripts and their notation in popular editors are shown in this table:

AutoIt Notation Notepad Notepad++ SciTE (AutoIt Default Editor)
UTF8 without BOM ANSI or UTF-8 depending on content (will force a BOM if saved) UTF-8 without BOM UTF-8
UTF8 with BOM UTF-8 UTF-8 UTF-8 with BOM
ANSI ANSI ANSI 8 bit / Code Page Property
UTF16 Little Endian Unicode UCS-2 Little Endian UCS-2 Little Endian
UTF16 Little Endian without BOM Unicode (will force a BOM if saved) UCS-2 Little Endian without BOM (can't be selected) Unsupported
UTF16 Big Endian Unicode big endian UCS-2 Big Endian UCS-2 Big Endian
UTF16 Big Endian without BOM Unsupported UCS-2 Big Endian without BOM (can't be selected) Unsupported


The recommended script format is UTF-8 with BOM as that works best with notepad.exe and the AutoIt editor SciTe and guards against scripts unintentionally getting saved in a particular code page.

ANSI formats are not recommended as they can cause problems when run on machines with different locales.

UTF16 BE or LE without a BOM are not recommended. They are widely unsupported. Even with a BOM they are not particularly common and they take up much more disk space than UTF8.

  • File operations on text files not opened with FileOpen() and explicit unicode flags auto-detect encoding similar to most modern editors. This includes all file functions that are used with a filename, for example FileRead("filename.txt"). Specifically:
  • Current Limitations

    There are a few parts of AutoIt that don't yet have full Unicode support. These are:

    These limits will be addressed in future versions if possible.