CONVERTCP
Text File Codepage Converter for the Windows command line
This command line utility is a codepage converter to be used to change the character encoding of text. It fully supports charsets such as ANSI code pages, UTF-8, UTF-16 LE/BE, UTF-32 LE/BE, and EBCDIC. It's designed to convert big text files, too. It runs on Windows XP onwards (tested on XP, Windows 7, Windows 8.1, Windows 10, and Windows 11). The "readme.txt" file and the Wiki gives you some more information.
You'll find the compiled tool for 32 bit (x86) and 64 bit (x64) Windows in the "bin" directory. The C source code is available in the "src" directory. Just click on the "Files" tab.
Regardless if you have or don't have a SourceForge account - whenever you have questions about CONVERTCP or you want to give feedback then you are welcome to post it in the forum. Click on the "Discussion" tab.