conversion.js

function stringTohex(string) { 
  // convert to base64
  const base64encoded = btoa(string);

  // convert to array
  const arr = base64encoded.split('');

  // convert to string to char code
  const charCodes = arr.map((letter) => letter.charCodeAt());

  // convert to hex
  const secret = charCodes.map((code) => code.toString(16));
  
  return secret.join(' ');
}

function stringTohexTerse(string) {
  return btoa(string).split('').map((a) => a.charCodeAt().toString(16)).join(' ');
}

function hexToString(hex) {
  // explode hex to array
  const hexArr = hex.split(' ');
  
  // convert to char code
  const charCodes = hexArr.map((hex) => parseInt(hex, 16));
  
  // convert to char
  const base64String = charCodes.map((code) => String.fromCharCode(code)).join('');
  
  // decode base64
  return atob(base64String);
}

function hexToStringTerse(hex) {
  return atob(hex.split(' ').map((a) => String.fromCharCode(parseInt(a, 16))).join(''));
}

/**
  Example usage:

  const url = 'http://nathanstilwell.com';
  const hex = stringTohexTerse(url);
  const back = hexToString(hex);
  
  console.log( `url: ${url} => hex: ${hex}` );
  console.log( `hex: ${hex} => url: ${back}` );
*/