Base64 Encode / Decode

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It is widely used in web development, email systems, and data transmission protocols to safely encode binary data — such as images, files, and authentication credentials — into a text format that can be transmitted over text-based protocols without data corruption.

Our free online Base64 encoder and decoder lets you quickly convert plain text to Base64 encoding and vice versa. This is essential for developers working with APIs, data URIs, email attachments (MIME encoding), JSON Web Tokens (JWT), and many other web technologies that rely on Base64 encoding.

The tool supports full Unicode text encoding and decoding, handles special characters correctly, and provides instant conversion with error detection. Whether you need to encode a string for an API header, decode a Base64-encoded configuration value, or debug data transmission issues, this tool has you covered.

All encoding and decoding happens entirely in your browser using built-in JavaScript functions. No data is ever sent to a server, making this tool safe for encoding sensitive information like API keys or authentication tokens.

1. Select the mode — Choose "Encode" to convert plain text to Base64, or "Decode" to convert Base64 back to plain text.
2. Enter your input — Type or paste your text (for encoding) or Base64 string (for decoding) in the input area.
3. Click Convert — Press the Encode or Decode button to perform the conversion.
4. Copy the result — Click the Copy Output button to copy the result to your clipboard.
5. Use Swap — Click the Swap button to quickly reverse the operation, using the output as the new input.