Base64 format is useful for encoding arbitrary binary information as, for example,  *.exe files, encrypted messages, cryptographic keys, audio and image files, for transmission by electronic mail.  The application applies the freeware executable published by  John Walker (http://www.fourmilab.ch) and allows to encode list of bytes, containing arbitrary values, 0 including, to base64 string format and decode obtained string again into list of bytes. Similarly it is possible to encode/decode arbitrary files. File encoded to base64 format has original file name with the added extension *.b64. For safety reasons,  name of the decoded file is the concatenation of an original file name and  dash character (_).