Web and XML Glossary

Base64 encoding is designed to represent arbitrary sequences of octets in a form that need not be humanly readable. The encoding and decoding Algorithms are simple, but the encoded data are consistently only about 33 percent larger than the unencoded data. In Base64, a 65-character subset of ASCII is used, enabling 6 bits to be represented per printable character. Base64 is virtually identical to the encoding used in PEM applications.