base64-js does basic base64 encoding/decoding in pure JS.

build status

Many browsers already have base64 encoding/decoding functionality, but it is for text data, not all-purpose binary data.

Sometimes encoding/decoding binary data in the browser is useful, and that is what this module does.


With npm do:

npm install base64-js and var base64js = require('base64-js')

For use in web browsers do:

<script src="base64js.min.js"></script>


base64js has three exposed functions, byteLength, toByteArray and fromByteArray, which both take a single argument.

  • byteLength - Takes a base64 string and returns length of byte array
  • toByteArray - Takes a base64 string and returns a byte array
  • fromByteArray - Takes a byte array and returns a base64 string