Base64 Encoder/Decoder 1.5.1.1
ase64 is the simple command line Windows utility program used to encode and decode files in the “Base64” format. It allows to save results to the file or redirect it to the standard output. Program is suitable for use in automated batch processing.
You can download executable or zipped program version (no setup needed - it's just one small file) or C# source code if you like to see how it was coded or if you want to extend id and build your own functionality on top of of. You can download it and use for free.