Base64 Encode / Decode

Encode text to Base64 and decode Base64 strings online. Full Unicode/UTF-8 support. Free, fast, client-side Base64 converter tool.

Everything runs in your browser — your data is never sent to any server.

Why Use the Base64 Encoder/Decoder?

Base64 encoding is used everywhere in web development — from data URLs and email attachments to JWT tokens and API payloads. Our tool provides a quick way to encode and decode Base64 with full Unicode support, ensuring international text is handled correctly.

Key Features

  • Two-tab interface: separate Encode and Decode modes
  • Full Unicode/UTF-8 support for international characters
  • Swap button to instantly switch encoded and decoded content
  • One-click paste from clipboard and copy to clipboard

How to Use

  1. Select the Encode or Decode tab
  2. Paste your text or Base64 string in the input area
  3. Click the action button and copy the result

Technical Details

Encoding uses btoa() with a Unicode-safe approach: text is first encoded as UTF-8 bytes via encodeURIComponent/unescape, then converted to Base64. Decoding reverses this process using atob() and decodeURIComponent/escape. This ensures all Unicode characters are correctly handled, not just ASCII.

FAQ

Does this support non-English characters?

Yes, our tool uses UTF-8 encoding before Base64 conversion, so all Unicode characters including Chinese, Arabic, and emoji are supported.

What's the difference between encodeURI and Base64?

Base64 converts any binary data to ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). URL encoding converts special characters to %XX format. They serve different purposes.

Related tools