btoa vs third party base64 encoder

JavaScript performance comparison

Revision 8 of this test case created by Xotic750

Info

Encoding large data in base64 can be slow. Also, native implementations of btoa do not correctly handle utf-8 characters. Searching for the best performing alternative.

Preparation code

<script src="//utility-js.googlecode.com/files/utility3.js"></script>
<script>
Benchmark.prototype.setup = function() {
    /**
     *
     *  Base64 encode / decode
     *  http://www.webtoolkit.info/
     *
     **/

   
    Base64 = {
   
      // private property
      _keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
   
      // public method for encoding
      encode: function(input) {
        var output = "";
        var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
        var i = 0;
   
        input = Base64._utf8_encode(input);
   
        while (i < input.length) {
   
          chr1 = input.charCodeAt(i++);
          chr2 = input.charCodeAt(i++);
          chr3 = input.charCodeAt(i++);
   
          enc1 = chr1 >> 2;
          enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
          enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
          enc4 = chr3 & 63;
   
          if (isNaN(chr2)) {
            enc3 = enc4 = 64;
          } else if (isNaN(chr3)) {
            enc4 = 64;
          }
   
          output = output + this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) + this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
   
        }
   
        return output;
      },
   
      // public method for decoding
      decode: function(input) {
        var output = "";
        var chr1, chr2, chr3;
        var enc1, enc2, enc3, enc4;
        var i = 0;
   
        input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
   
        while (i < input.length) {
   
          enc1 = this._keyStr.indexOf(input.charAt(i++));
          enc2 = this._keyStr.indexOf(input.charAt(i++));
          enc3 = this._keyStr.indexOf(input.charAt(i++));
          enc4 = this._keyStr.indexOf(input.charAt(i++));
   
          chr1 = (enc1 << 2) | (enc2 >> 4);
          chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
          chr3 = ((enc3 & 3) << 6) | enc4;
   
          output = output + String.fromCharCode(chr1);
   
          if (enc3 != 64) {
            output = output + String.fromCharCode(chr2);
          }
          if (enc4 != 64) {
            output = output + String.fromCharCode(chr3);
          }
   
        }
   
        output = Base64._utf8_decode(output);
   
        return output;
   
      },
   
      // private method for UTF-8 encoding
      _utf8_encode: function(string) {
        string = string.replace(/\r\n/g, "\n");
        var utftext = "";
   
        for (var n = 0; n < string.length; n++) {
   
          var c = string.charCodeAt(n);
   
          if (c < 128) {
            utftext += String.fromCharCode(c);
          } else if ((c > 127) && (c < 2048)) {
            utftext += String.fromCharCode((c >> 6) | 192);
            utftext += String.fromCharCode((c & 63) | 128);
          } else {
            utftext += String.fromCharCode((c >> 12) | 224);
            utftext += String.fromCharCode(((c >> 6) & 63) | 128);
            utftext += String.fromCharCode((c & 63) | 128);
          }
   
        }
   
        return utftext;
      },
   
      // private method for UTF-8 decoding
      _utf8_decode: function(utftext) {
        var string = "";
        var i = 0;
        var c = c1 = c2 = 0;
   
        while (i < utftext.length) {
   
          c = utftext.charCodeAt(i);
   
          if (c < 128) {
            string += String.fromCharCode(c);
            i++;
          } else if ((c > 191) && (c < 224)) {
            c2 = utftext.charCodeAt(i + 1);
            string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
            i += 2;
          } else {
            c2 = utftext.charCodeAt(i + 1);
            c3 = utftext.charCodeAt(i + 2);
            string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
            i += 3;
          }
   
        }
   
        return string;
      }
   
    }
   
    chr = function(code) {
      return String.fromCharCode(code);
    };
   
    //returns utf8 encoded charachter of a unicode value.
    //code must be a number indicating the Unicode value.
    //returned value is a string between 1 and 4 charachters.
    code2utf = function(code) {
      if (code < 128) return chr(code);
      if (code < 2048) return chr(192 + (code >> 6)) + chr(128 + (code & 63));
      if (code < 65536) return chr(224 + (code >> 12)) + chr(128 + ((code >> 6) & 63)) + chr(128 + (code & 63));
      if (code < 2097152) return chr(240 + (code >> 18)) + chr(128 + ((code >> 12) & 63)) + chr(128 + ((code >> 6) & 63)) + chr(128 + (code & 63));
    };
   
    //it is a private function for internal use in utf8Encode function
    _utf8Encode = function(str) {
      var utf8str = new Array();
      for (var i = 0; i < str.length; i++) {
        utf8str[i] = code2utf(str.charCodeAt(i));
      }
      return utf8str.join('');
    };
   
    //Encodes a unicode string to UTF8 format.
    utf8Encode = function(str) {
      var utf8str = new Array();
      var pos, j = 0;
      var tmpStr = '';
   
      while ((pos = str.search(/[^\x00-\x7F]/)) != -1) {
        tmpStr = str.match(/([^\x00-\x7F]+[\x00-\x7F]{0,10})+/)[0];
        utf8str[j++] = str.substr(0, pos);
        utf8str[j++] = _utf8Encode(tmpStr);
        str = str.substr(pos + tmpStr.length);
      }
   
      utf8str[j++] = str;
      return utf8str.join('');
    };
   
    function encodeBase64(str) {
      var chr1, chr2, chr3, rez = '',
          arr = [],
          i = 0,
          j = 0,
          code = 0;
      var chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='.split('');
   
      while (code = str.charCodeAt(j++)) {
        if (code < 128) {
          arr[arr.length] = code;
        } else if (code < 2048) {
          arr[arr.length] = 192 | (code >> 6);
          arr[arr.length] = 128 | (code & 63);
        } else if (code < 65536) {
          arr[arr.length] = 224 | (code >> 12);
          arr[arr.length] = 128 | ((code >> 6) & 63);
          arr[arr.length] = 128 | (code & 63);
        } else {
          arr[arr.length] = 240 | (code >> 18);
          arr[arr.length] = 128 | ((code >> 12) & 63);
          arr[arr.length] = 128 | ((code >> 6) & 63);
          arr[arr.length] = 128 | (code & 63);
        }
      };
   
      while (i < arr.length) {
        chr1 = arr[i++];
        chr2 = arr[i++];
        chr3 = arr[i++];
   
        rez += chars[chr1 >> 2];
        rez += chars[((chr1 & 3) << 4) | (chr2 >> 4)];
        rez += chars[chr2 === undefined ? 64 : ((chr2 & 15) << 2) | (chr3 >> 6)];
        rez += chars[chr3 === undefined ? 64 : chr3 & 63];
      };
      return rez;
    };
   
    // based on Kevin van Zonneveld (http://kevin.vanzonneveld.net), original by Webtoolkit.info (http://www.webtoolkit.info/)
    // improved by: sowberry, Yves Sucaet, kirilloid
    // bugfixed by: Onno Marsman, Onno Marsman, Ulrich, Rafal Kukawski
    // tweaked by: Jack
   
    function utf8_encode(a) {
      var d = 0,
          b = 0,
          c = "",
          f, e;
      if (null === a || "undefined" === typeof a) {
        return ""
      }
      a += "";
      f = a.length;
      for (var g = 0; g < f; g++) {
        e = a.charCodeAt(g), crt_encode = null, 128 > e ? d++ : crt_encode = 127 < e && 2048 > e ? String.fromCharCode(e >> 6 | 192, e & 63 | 128) : String.fromCharCode(e >> 12 | 224, e >> 6 & 63 | 128, e & 63 | 128), null !== crt_encode && (d > b && (c += a.slice(b, d)), c += crt_encode, b = d = g + 1)
      }
      d > b && (c += a.slice(b, f));
      return c
    }
    // based on http://www.webtoolkit.info/
   
    function base64_encode(a) {
      var d = "",
          b, c, f, e, g, h, j = 0,
          k;
      a = utf8_encode(a);
      for (k = a.length; j < k;) {
        b = a.charCodeAt(j++), c = a.charCodeAt(j++), f = a.charCodeAt(j++), e = b >> 2, b = (b & 3) << 4 | c >> 4, g = (c & 15) << 2 | f >> 6, h = f & 63, isNaN(c) ? g = h = 64 : isNaN(f) && (h = 64), d += "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".charAt(e) + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".charAt(b) + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".charAt(g) + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".charAt(h)
      }
      return d
    }
   
    a = "";
    for (var i = 0; i < 100; i++)
    a += "teststring ";
};
</script>

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

Testing in unknown unknown
Test Ops/sec
Native btoa function
b = btoa(a);
pending…
javascript btoa
b = Base64.encode(a);
pending…
native btoa with javscript utf-8 encode
b = btoa(Base64._utf8_encode(a));
pending…
native btoa with native utf-8 encoding
b = btoa(unescape(encodeURIComponent(a)));
pending…
native btoa with javascript utf-8 #2
b = btoa(utf8Encode(a));
pending…
Javascript btoa #2 (encodeBase64)
b = encodeBase64(a);
pending…
native btoa with javascript utf8_encode
b = btoa(utf8_encode(a));
pending…
base64_encode with javascript utf8_encode
b = base64_encode(utf8_encode(a));
pending…
$u.btoa
b = $u.btoa(a);
pending…
$u.btoa with $u.Utf8encode
b = $u.btoa($u.utf8Encode(a));
pending…

Compare results of other browsers

Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:

0 comments

Add a comment