Base64 Encoder/Decoder

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Welcome to b64codec.com a Base64 Encoder/Decoder

All encoding and decoding operations on this site are performed directly in your web browser.

Base64 Encoder/Decoder Explianed

1. Binary Data to ASCII: Base64 converts binary data into a set of 64 different ASCII characters. These characters include:

• Uppercase letters: A-Z (26 characters)
• Lowercase letters: a-z (26 characters)
• Digits: 0-9 (10 characters)
• Plus (+) and slash (/) (2 characters)
• Equals sign (=) is used for padding

2. Grouping Bits: The binary data is divided into groups of 6 bits because 2^6 = 64, which fits perfectly into the 64 different ASCII characters.

3. Padding: If the total number of bits in the binary data is not a multiple of 6, padding is added. The padding character = is used to make the final group of bits a full 6 bits.

4. Encoding Process:

Convert the binary data to a string of bits.
Split the string of bits into chunks of 6 bits.
Convert each 6-bit chunk into a decimal number.
Plus (+) and slash (/) (2 characters)
Map each decimal number to its corresponding Base64 character.

5. Example:

Suppose we have the ASCII string "ABC".
Convert "ABC" to binary: A = 01000001, B = 01000010, D = 01000011.
Combine the binary: 010000010100001001000011.
Split into 6-bit chunks: 010000, 010100, 001001, 000011.
Convert each chunk to decimal: 16, 20, 9, 3.
Map to Base64 characters: Q, U, J, D Using the Base64 Array.
The Base64 encoded string is "QUJD".

6. Decoding: The process of decoding Base64 is the reverse of encoding. Each Base64 character is converted back to its 6-bit binary form, concatenated, and then split into 8-bit bytes to retrieve the original binary data.