base64 [OPTION] [FILE]

-w, --wrap=COLS
    Wrap encoded lines after COLS character (default 76). Use 0 to disable line wrapping.
-d, --decode
    Decode data.
-i, --ignore-garbage
    When decoding, ignore non-alphabet characters.
--help
    display this help and exit
--version
    output version information and exit

echo EncodeMe | base64 -e

echo RW5jb2RlTWU= | base64 -d

base64 file1 > encodedfile1

base64 -d encodedfile1 > file1