Base64 Decode

Definition

Base64 decoding is the process of converting a string of Base64-encoded ASCII text back into its original binary format. Base64 encoding is commonly used for secure data transmission over text-based channels, such as email or web pages. Decoding the encoded data allows the recipient to retrieve the original binary data.

The Base64 encoding process converts binary data into 6-bit values and represents those values as characters from a 64-character set. Each set of four characters in the encoded string corresponds to three bytes of binary data. To decode the Base64-encoded string, the decoding algorithm reads the input string in groups of four characters and converts them back into three bytes of binary data.

If the input string is not an exact multiple of four characters, padding characters ("=") are added to the end of the string to ensure that it can be divided into groups of four. These padding characters are discarded during the decoding process.

Base64 decoding is used in a variety of applications where binary data is transmitted or stored as text. For example, it is commonly used to decode email attachments or to extract images from HTML documents that have been encoded as Base64 strings.

In summary, Base64 decoding is the process of converting Base64-encoded ASCII text back into its original binary format. This process is essential for retrieving the original binary data that has been transmitted or stored as text using Base64 encoding.