UTF8Tool is an application to encode files to the UTF-8  character set and vice-versa.  You can download the application here.  This application was originally created for a user who needed to decode/encode files stored in a text column in his database.

To use the application, select the option to either decode or encode the files.  Then enter a search pattern in the Input folder option to locate your files.  If we wanted to process only pdf files, we could enter something like this:

Next, enter the folder to store the processed files in, in the Output folder option e.g.

Once you’ve entered the values, click on the Start button to process your files.  Note that any existing files in the output folder will be overwritten.