Base64 Encoder/Decoder

Base64 is an encoding scheme that converts binary data into a string of ASCII characters using 64 printable symbols (A-Z, a-z, 0-9, +, /). It is not encryption — anyone can decode it instantly. Its purpose is to safely transport binary data through systems that only handle text, like email (MIME attachments), JSON payloads, data URIs in HTML and CSS, and HTTP headers like Basic Authentication. The encoded output is about 33% larger than the original data.

Embedding small images directly in CSS or HTML as data URIs avoids an extra HTTP request — useful for icons under a few kilobytes. API tokens and credentials in HTTP Basic Auth are Base64-encoded (though not secured — always use HTTPS). Email attachments use Base64 to embed binary files in the text-based MIME format. JWT tokens encode their header and payload segments as Base64url (a URL-safe variant that replaces + and / with - and _).