Base64 Encode / Decode

Encode text to Base64 or decode Base64 strings. All processing happens in your browser.

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data as an ASCII string. It is commonly used to embed binary data in text-based formats such as JSON, XML, HTML, and email (MIME). Each Base64 digit represents exactly 6 bits of data, meaning three bytes of input produce four characters of Base64 output.

Common Use Cases

  • Embedding images in CSS or HTML via data URIs
  • Encoding binary attachments in email (MIME)
  • Transmitting binary data over text-only protocols
  • Encoding credentials for HTTP Basic Authentication
  • Storing binary blobs in JSON or XML payloads

How This Tool Works

This tool uses your browser's built-in btoa() and atob() functions with proper Unicode support. Your data is never sent to a server -- everything runs entirely client-side. Toggle between Encode and Decode mode, type or paste your text, and see the result instantly.