Click here for Live demo  of Javascript password generator

The code :

<script language="javascript">
<!-- //hide
  // Javascript password generator
  // By moshahmed,
  // 1 Based on http://www.weberdev.com/get_example-3338.html
  //   JSPassGen v2.1 by Ummon <jeffhawke@iname.com>
  // 2 Based on Jpass v1.1 (Kelv 2000 kelv@kelv.net)
  //   http://freshmeat.net/projects/jpass/

var randu_seed; // hex string = MD5(passwords).
var randu_index = 0;
function randu_setup(seed) {
  document.pswd4.pass4hash.value=randu_seed=seed;
  randu_index = 0;
}

function randu(min,max) { // return in [min..max-1]
  if (!randu_seed) {
    return min + Math.floor(Math.random()*(max-min));
  } else {
    var range = max - min;
    if (range <= 1) { // avoid % dividing by zero.
      return min;
    }
    var hexlen = 1; // was: Math.ceil(Math.log(range)/Math.log(16));
    var hexit = randu_seed.substr(randu_index, 4);
    randu_index = (randu_index + hexlen) % randu_seed.length;
    var pran = parseInt(hexit,16);
    var prani = min + pran % range;
    // console.debug(hexit, min,max,prani);
    return prani;
  }
};

function pickonefrom(arr) { // Return random number for indexing arr.
  return randu(0, arr.length);
};

function pickone(arr) { // pick one from array of arg;
  return arr[pickonefrom(arr)];
};

function normalRandom() {
  var sum = 0;
  for(var i=0;i<12;i++) {
    sum += Math.random();
  }
  return (sum - 6.0)/6.0
};

function expandChoices(str, frac) {
  // Context free phrase generator.
  // Usage:
  //  expandChoices("(1|2)(a|b)",0) = "1a"
  //  expandChoices("(1|2)(a|b)",1) = "2b"
  // Args:
  //  str: is parethesized expression with choices,
  //  frac: 0..1 to pick a particular choice, or -1 for random pick.
  // Also see: ../pascal/slib.pas:125:select
  // console.debug("expandChoices '%s'.", str);
  var lp, rp;
  var lchar = '(', rchar = ')', spliton = '|'; // could be {,}.
  // recursively remove all parenthesis, starting with innermost.
  // how: find the first close parent, scan back for matching open paren.
  while ((rp = str.indexOf(rchar)) != -1) {
    lp = str.substr(0,rp).lastIndexOf(lchar);
    if (lp != -1) {
      var left = str.substr(0,lp);
      var mid = str.substr(lp+1, rp-lp-1);
      var right = str.substr(rp+1);
      str = left + expandChoices(mid, frac) + right;
    } else {
      console.debug("error: missing lchar=%s in '%s'.", lchar, str);
      return "";
    }
  }
  if( (lp = str.lastIndexOf(lchar)) != -1) {
    console.debug("error: missing rchar=%s in '%s'.", rchar, str);
    return "";
  }
  // Split "a|b|c" and return one of the elements.
  if (str.indexOf(spliton) != -1) {
    var arr = str.split(spliton);
    if (arr.length < 1) {
      return "";
    }
    // If frac is given, use it, otherwise pickone randomly.
    if (0 <= frac && frac <= 1) {
      var idx = Math.floor(frac * arr.length);
      if (idx < 0) idx = 0;
      if (idx >= arr.length) idx = arr.length-1;
      str = arr[idx];
    } else {
      str = pickone(arr);
    }
  }
  return str;
};

function mkpass(pass_len, num_letters, num_digits, num_separators, char_separators, seed) {
  // Make and return a password, that is pass_len long, containing
  // num_letters, num_digits, num_separators from char_separators.
  var digits = '123456789';
  var vowels = 'aeiou';
  var consonants = 'bcdfghjklmnpqrstvwxyz';
  var CONSONANTS = consonants.toUpperCase();
  var VOWELS = vowels.toUpperCase();
  var charsets = [consonants, CONSONANTS, vowels, VOWELS];

  var ps= '';

  randu_setup(seed);
  // Add some 4 chars syllables.
  while(num_letters > 0){
      ps += pickone(CONSONANTS); if (--num_letters <1) break;
      ps += pickone(vowels);     if (--num_letters <1) break;
      ps += pickone(consonants); if (--num_letters <1) break;
      ps += pickone(vowels);     if (--num_letters <1) break;
  }
 
  // Add separators.
  while (num_separators-- > 0) {
    ps += pickone(char_separators);
  }

  // Add digits.
  while(num_digits-- > 0){
    ps += pickone(digits);
  }

  // Pad to pass_len.
  while(ps.length < pass_len) {
    if (char_separators.length > 0) {
      ps += pickone(char_separators);
    } else {
      var charset = pickone(charsets);
      ps += pickone(charset);
    }
  }

  // Truncate to pass_len.
  if (ps.length > pass_len) {
    ps = ps.substr(0,pass_len);
  }

  return ps;
};

var MD5 = function(string) {
  /**
  *  http://www.webtoolkit.info/javascript-md5.html
  *  MD5 (Message-Digest Algorithm)
  *  http://www.webtoolkit.info/
  *
  **/
    function RotateLeft(lValue, iShiftBits) {
        return (lValue<<iShiftBits) | (lValue>>>(32-iShiftBits));
    }
 
    function AddUnsigned(lX,lY) {
        var lX4,lY4,lX8,lY8,lResult;
        lX8 = (lX & 0x80000000);
        lY8 = (lY & 0x80000000);
        lX4 = (lX & 0x40000000);
        lY4 = (lY & 0x40000000);
        lResult = (lX & 0x3FFFFFFF)+(lY & 0x3FFFFFFF);
        if (lX4 & lY4) {
            return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
        }
        if (lX4 | lY4) {
            if (lResult & 0x40000000) {
                return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
            } else {
                return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
            }
        } else {
            return (lResult ^ lX8 ^ lY8);
        }
     }
 
     function F(x,y,z) { return (x & y) | ((~x) & z); }
     function G(x,y,z) { return (x & z) | (y & (~z)); }
     function H(x,y,z) { return (x ^ y ^ z); }
    function I(x,y,z) { return (y ^ (x | (~z))); }
 
    function FF(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
 
    function GG(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
 
    function HH(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
 
    function II(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
 
    function ConvertToWordArray(string) {
        var lWordCount;
        var lMessageLength = string.length;
        var lNumberOfWords_temp1=lMessageLength + 8;
        var lNumberOfWords_temp2=(lNumberOfWords_temp1-(lNumberOfWords_temp1 % 64))/64;
        var lNumberOfWords = (lNumberOfWords_temp2+1)*16;
        var lWordArray=Array(lNumberOfWords-1);
        var lBytePosition = 0;
        var lByteCount = 0;
        while ( lByteCount < lMessageLength ) {
            lWordCount = (lByteCount-(lByteCount % 4))/4;
            lBytePosition = (lByteCount % 4)*8;
            lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount)<<lBytePosition));
            lByteCount++;
        }
        lWordCount = (lByteCount-(lByteCount % 4))/4;
        lBytePosition = (lByteCount % 4)*8;
        lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80<<lBytePosition);
        lWordArray[lNumberOfWords-2] = lMessageLength<<3;
        lWordArray[lNumberOfWords-1] = lMessageLength>>>29;
        return lWordArray;
    };
 
    function WordToHex(lValue) {
        var WordToHexValue="",WordToHexValue_temp="",lByte,lCount;
        for (lCount = 0;lCount<=3;lCount++) {
            lByte = (lValue>>>(lCount*8)) & 255;
            WordToHexValue_temp = "0" + lByte.toString(16);
            WordToHexValue = WordToHexValue + WordToHexValue_temp.substr(WordToHexValue_temp.length-2,2);
        }
        return WordToHexValue;
    };
 
    function Utf8Encode(string) {
        string = string.replace(/ /g," ");
        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;
    };
 
    var x=Array();
    var k,AA,BB,CC,DD,a,b,c,d;
    var S11=7, S12=12, S13=17, S14=22;
    var S21=5, S22=9 , S23=14, S24=20;
    var S31=4, S32=11, S33=16, S34=23;
    var S41=6, S42=10, S43=15, S44=21;
 
  //console.debug('string='+string+'.');
    string = Utf8Encode(string);
 
    x = ConvertToWordArray(string);
 
    a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476;
 
    for (k=0;k<x.length;k+=16) {
        AA=a; BB=b; CC=c; DD=d;
        a=FF(a,b,c,d,x[k+0], S11,0xD76AA478);
        d=FF(d,a,b,c,x[k+1], S12,0xE8C7B756);
        c=FF(c,d,a,b,x[k+2], S13,0x242070DB);
        b=FF(b,c,d,a,x[k+3], S14,0xC1BDCEEE);
        a=FF(a,b,c,d,x[k+4], S11,0xF57C0FAF);
        d=FF(d,a,b,c,x[k+5], S12,0x4787C62A);
        c=FF(c,d,a,b,x[k+6], S13,0xA8304613);
        b=FF(b,c,d,a,x[k+7], S14,0xFD469501);
        a=FF(a,b,c,d,x[k+8], S11,0x698098D8);
        d=FF(d,a,b,c,x[k+9], S12,0x8B44F7AF);
        c=FF(c,d,a,b,x[k+10],S13,0xFFFF5BB1);
        b=FF(b,c,d,a,x[k+11],S14,0x895CD7BE);
        a=FF(a,b,c,d,x[k+12],S11,0x6B901122);
        d=FF(d,a,b,c,x[k+13],S12,0xFD987193);
        c=FF(c,d,a,b,x[k+14],S13,0xA679438E);
        b=FF(b,c,d,a,x[k+15],S14,0x49B40821);
        a=GG(a,b,c,d,x[k+1], S21,0xF61E2562);
        d=GG(d,a,b,c,x[k+6], S22,0xC040B340);
        c=GG(c,d,a,b,x[k+11],S23,0x265E5A51);
        b=GG(b,c,d,a,x[k+0], S24,0xE9B6C7AA);
        a=GG(a,b,c,d,x[k+5], S21,0xD62F105D);
        d=GG(d,a,b,c,x[k+10],S22,0x2441453);
        c=GG(c,d,a,b,x[k+15],S23,0xD8A1E681);
        b=GG(b,c,d,a,x[k+4], S24,0xE7D3FBC8);
        a=GG(a,b,c,d,x[k+9], S21,0x21E1CDE6);
        d=GG(d,a,b,c,x[k+14],S22,0xC33707D6);
        c=GG(c,d,a,b,x[k+3], S23,0xF4D50D87);
        b=GG(b,c,d,a,x[k+8], S24,0x455A14ED);
        a=GG(a,b,c,d,x[k+13],S21,0xA9E3E905);
        d=GG(d,a,b,c,x[k+2], S22,0xFCEFA3F8);
        c=GG(c,d,a,b,x[k+7], S23,0x676F02D9);
        b=GG(b,c,d,a,x[k+12],S24,0x8D2A4C8A);
        a=HH(a,b,c,d,x[k+5], S31,0xFFFA3942);
        d=HH(d,a,b,c,x[k+8], S32,0x8771F681);
        c=HH(c,d,a,b,x[k+11],S33,0x6D9D6122);
        b=HH(b,c,d,a,x[k+14],S34,0xFDE5380C);
        a=HH(a,b,c,d,x[k+1], S31,0xA4BEEA44);
        d=HH(d,a,b,c,x[k+4], S32,0x4BDECFA9);
        c=HH(c,d,a,b,x[k+7], S33,0xF6BB4B60);
        b=HH(b,c,d,a,x[k+10],S34,0xBEBFBC70);
        a=HH(a,b,c,d,x[k+13],S31,0x289B7EC6);
        d=HH(d,a,b,c,x[k+0], S32,0xEAA127FA);
        c=HH(c,d,a,b,x[k+3], S33,0xD4EF3085);
        b=HH(b,c,d,a,x[k+6], S34,0x4881D05);
        a=HH(a,b,c,d,x[k+9], S31,0xD9D4D039);
        d=HH(d,a,b,c,x[k+12],S32,0xE6DB99E5);
        c=HH(c,d,a,b,x[k+15],S33,0x1FA27CF8);
        b=HH(b,c,d,a,x[k+2], S34,0xC4AC5665);
        a=II(a,b,c,d,x[k+0], S41,0xF4292244);
        d=II(d,a,b,c,x[k+7], S42,0x432AFF97);
        c=II(c,d,a,b,x[k+14],S43,0xAB9423A7);
        b=II(b,c,d,a,x[k+5], S44,0xFC93A039);
        a=II(a,b,c,d,x[k+12],S41,0x655B59C3);
        d=II(d,a,b,c,x[k+3], S42,0x8F0CCC92);
        c=II(c,d,a,b,x[k+10],S43,0xFFEFF47D);
        b=II(b,c,d,a,x[k+1], S44,0x85845DD1);
        a=II(a,b,c,d,x[k+8], S41,0x6FA87E4F);
        d=II(d,a,b,c,x[k+15],S42,0xFE2CE6E0);
        c=II(c,d,a,b,x[k+6], S43,0xA3014314);
        b=II(b,c,d,a,x[k+13],S44,0x4E0811A1);
        a=II(a,b,c,d,x[k+4], S41,0xF7537E82);
        d=II(d,a,b,c,x[k+11],S42,0xBD3AF235);
        c=II(c,d,a,b,x[k+2], S43,0x2AD7D2BB);
        b=II(b,c,d,a,x[k+9], S44,0xEB86D391);
        a=AddUnsigned(a,AA);
        b=AddUnsigned(b,BB);
        c=AddUnsigned(c,CC);
        d=AddUnsigned(d,DD);
    }
 
    var temp = WordToHex(a)+WordToHex(b)+WordToHex(c)+WordToHex(d);
 
    return temp.toLowerCase();
};
// -->
</script>