Base64 Encoder & Decoder: Convert Text and Data Online
Base64 encoding is a method of converting binary data into ASCII text format. It is widely used in web development, email systems, and data transmission protocols where binary data needs to be represented as text. Our free online Base64 converter lets you encode and decode strings instantly in your browser.
The Base64 encoding scheme uses 64 characters (A-Z, a-z, 0-9, +, /) to represent binary data. Each Base64 digit represents 6 bits of data, meaning that three bytes of input produce four characters of Base64 output. This makes Base64-encoded data approximately 33% larger than the original, but ensures safe transmission across text-only channels.
Common use cases for Base64 encoding include embedding images directly in HTML or CSS (data URIs), encoding email attachments via MIME, transmitting binary data in JSON or XML APIs, and storing complex data in cookies or URL parameters. Developers frequently use Base64 when working with JWT tokens, API authentication, and data serialization.
This tool handles Unicode text correctly using UTF-8 encoding, so you can encode text in any language including characters with accents, Asian scripts, and emoji. The decoder will detect and properly handle invalid Base64 input, showing a clear error message if the encoded string is malformed.