Base64 Encoder

Base64 is a binary-to-text encoding scheme: it takes arbitrary bytes and represents them using only 64 printable ASCII characters (A-Z, a-z, 0-9, plus two symbols, usually + and /), padding the output with = characters to a multiple of four. It does this by regrouping the input's bits into 6-bit chunks rather than the usual 8-bit bytes, which is why encoded output is roughly a third larger than the original.

Base64 exists because many text-based protocols and formats — email (MIME), URLs, JSON, XML — can't safely carry arbitrary binary bytes, since certain byte values have special meaning or get mangled by encoding assumptions along the way. Encoding text or binary data as Base64 lets it travel safely through those channels as plain ASCII, which is why it shows up in things like embedding small images as data URIs, encoding Basic Auth credentials in HTTP headers, or storing binary blobs in JSON fields.

It's important to be clear that Base64 is an encoding, not encryption: it doesn't use a key, and anyone can decode it back to the original data in one step with no secret required. It should never be used as a way to protect sensitive information from being read.