Free Online Base64 Encoder/Decoder

Encode and decode text instantly.

About the Base64 Encoder/Decoder

This free online Base64 encoder and decoder uses a binary-to-text encoding scheme that represents binary data using a set of 64 ASCII characters. It is commonly used in web development to embed images in HTML or CSS, encode email attachments (MIME), transmit data in JSON web tokens (JWT), and handle data in systems that only support text-based formats.


Our Base64 Tool processes all encoding and decoding entirely in your browser using JavaScript's built-in btoa() and atob() functions. Your data never leaves your device, making it safe for encoding sensitive strings like API keys, configuration values, or authentication tokens during development and debugging.

How to Encode and Decode

  1. Enter Text: Paste or type your content in the input field.
  2. Choose Action: Click "Encode" to convert to Base64, or "Decode" to convert from Base64.
  3. Copy Result: Click the copy button to save the output to your clipboard.

When to Use Base64

  • Data URIs: Embed small images directly in HTML or CSS files.
  • JWT Debugging: Decode JSON Web Tokens to inspect their payload.
  • API Development: Encode credentials for HTTP Basic Authentication headers.
  • Email Encoding: MIME encoding for binary attachments in email systems.