Base64 encoding and decoding in client-side Javascript

Question

Are there any methods in JavaScript that could be used to encode and decode a string using base64 encoding?

Answer 1

function b64_to_utf8( str ) {
  return decodeURIComponent(escape(window.atob( str )));
}

https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding#The_.22Unicode_Problem.22