base64-js does basic base64 encoding/decoding in pure JS.
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
var base64 = require('base64-js')
base64 has three exposed functions,
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