Encode plain text to Base64 or decode Base64 back to text with full Unicode support
Base64 is a binary-to-text encoding scheme that represents binary data using a set of 64 printable ASCII characters. It is commonly used to embed images in HTML or CSS, transmit binary data over text-based protocols such as email (MIME) and JSON web tokens (JWT), and store complex data in cookies or URL parameters. Any time a system only supports plain text but you need to send arbitrary bytes, Base64 is the standard solution.
The encoding process groups every three bytes of input into four Base64 characters, using the characters A-Z, a-z, 0-9, plus (+), and slash (/), with the equals sign (=) as padding. This means the encoded output is roughly 33% larger than the original data. Our tool handles full UTF-8 text by first converting Unicode strings into their byte representations using the TextEncoder API before applying the standard Base64 algorithm, ensuring that emojis, accented characters, and non-Latin scripts encode and decode correctly.
Developers frequently use Base64 encoding when embedding small assets inline, debugging authentication tokens, or preparing data for APIs that expect text payloads. This tool runs entirely in your browser, so no data is sent to any server. Paste your plain text and click Encode, or paste a Base64 string and click Decode -- the conversion happens instantly with no size limits other than your browser's memory.