Base64 Encode / Decode

Free Online Base64 Encoder / Decoder

Base64 encoding converts binary data into an ASCII string format using 64 printable characters (A-Z, a-z, 0-9, +, /). It is widely used for embedding images in HTML/CSS (data URIs), transmitting binary data in JSON APIs, encoding authentication credentials in HTTP headers, and storing binary data in text-based formats like XML or JSON. This tool supports both text and file input. To encode, type or paste text into the input area and click Encode. To decode a Base64 string back to plain text, switch to Decode mode and paste the encoded string. For file encoding, use the file upload area — the tool reads the file and produces its Base64 representation, which is useful for creating data URIs or preparing binary payloads for API calls.

Client-Side Base64 Processing

All Base64 encoding and decoding happens locally in your browser using the native btoa() and atob() functions, with proper UTF-8 handling for non-ASCII characters. For file inputs, the FileReader API reads the file contents directly on your device. No files or text are uploaded to any server, ensuring complete privacy for your sensitive data such as API tokens, private keys, and confidential documents. The tool also supports decoding Base64 data back to downloadable files — useful when you receive Base64-encoded binaries from an API and need to reconstruct the original file.