How It Works

This tool encodes and decodes text using the Base64 encoding scheme — entirely inside your browser. No data is ever sent to a server.

What is Base64?

Base64 is a binary-to-text encoding that represents binary data using 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It is commonly used to embed binary content (images, files) in text-based formats such as JSON, XML, HTML, and email (MIME). Every 3 bytes of input become 4 Base64 characters, so encoded output is roughly 33% larger than the original.

Implementation Details

The encoder uses JavaScript’s built-in btoa() function and the decoder uses atob() — both are available in every modern browser.

Because btoa() and atob() only handle Latin-1 (single-byte) characters, the tool adds a Unicode-safe layer:

• Encoding: The input string is first converted to UTF-8 bytes using the browser’s TextEncoder API. The resulting byte array is then mapped to a binary string and passed to btoa().
• Decoding: atob() produces a binary string which is then converted back to a Uint8Array and decoded as UTF-8 via TextDecoder.

This approach correctly handles any Unicode text, including emoji and non-Latin scripts, without relying on any third-party library.

Privacy

All encoding and decoding runs locally in your browser tab using standard JavaScript APIs. Your input text never leaves your device.