Convert from base64

Anyone knows any way to translate from base64 to normal text?
For example:

from base64:

eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ 

to Normal Text: 

{
"sub": "1234567890",
"name": "John Doe",
"iat": 1516239022
}

thanks for helping me to gruw up!.

  • I found this and it's beyond me, I'll leave it here in case someone else requires it too.
            var cadena= "HOLA";
            var cadenabase64= "SE9MQQ==";
            var options64 ={
                  :fromRepresentation => StringUtil.REPRESENTATION_STRING_BASE64,
                :toRepresentation  => StringUtil.REPRESENTATION_STRING_PLAIN_TEXT,
            };
            var options ={
                :fromRepresentation => StringUtil.REPRESENTATION_STRING_PLAIN_TEXT,
                :toRepresentation  => StringUtil.REPRESENTATION_STRING_BASE64,
               
            };
          var xx= StringUtil.convertEncodedString(cadena, options);
           var yy= StringUtil.convertEncodedString(cadenabase64, options64);
         
            System.println(""+xx);
             System.println(""+yy);