Base64 is an encoding and decoding technique used to convert binary data to an ASCII text format, and vice versa. It often serves to transfer binary data over the Internet using plain text mediums such as email (e.g., as MIME encoded multi-parts) and instant messages, or to embed binary data in text files as XML files, CSV files, PEM files and others.
Base64 works by dividing every three bits of binary data into six bit units. The newly created data is represented in a 64-radix numeral system and as seven-bit ASCII text. Because each bit is divided into two bits, the converted data is 33 percent, or one-third, larger than the original data.
Like binary data, Base64 encoded data is not human readable.