Base64 Encoder/Decoder is a free online tool that encodes text to Base64 format or decodes Base64 strings back to original text. Easily convert Base64 format frequently used in API development, web development, data transmission, email attachments, etc.
Useful when you need to transmit images or files as text, decode JWT tokens to check contents, or decrypt Base64 encoded data from API responses. An essential tool for developers, system administrators, and IT professionals, with one-click copy of conversion results.
The Base64 Converter is a mission-critical tool for developers, network engineers, and data analysts, facilitating the seamless encoding and decoding of binary data into a text-based ASCII string format. This tool ensures data integrity across systems that may not support raw binary transmission.
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format by translating it into a radix-64 representation. The term "Base64" typically refers to a specific MIME content transfer encoding. It uses a set of 64 characters: Uppercase A-Z (26), Lowercase a-z (26), Numbers 0-9 (10), "+", and "/". This specific 64-character set was chosen because it is part of the ASCII standard and is generally safe to send across different networks and systems without being modified.
In the early days of the internet, protocols like SMTP (Simple Mail Transfer Protocol) were designed to transfer 7-bit ASCII text. If you tried to send a binary file (like an image or executable) through these systems, the data would often get corrupted because some byte values were interpreted as control characters (e.g., end of file, new line). Base64 solves this by converting any binary data into safe, printable text characters.
The encoding process works by taking groups of three bytes (24 bits) of binary data. These 24 bits are then divided into four 6-bit chunks. Since 2^6 is 64, each 6-bit chunk maps perfectly to one character in the Base64 alphabet.
The Padding (=): If the total number of bytes is not divisible by 3, Base64 uses the "=" character as padding at the end of the string to tell the decoder how many bytes were in the final block. This ensures that the decoded data is byte-for-byte identical to the original.
While Base64 allows binary compliance, it comes at a cost: efficiency. Because every 3 bytes are converted into 4 characters, the file size increases by approximately 33%. Therefore, it is generally not recommended to Base64 encode very large files (like videos) for storage or transmission unless strictly necessary.