<!DOCTYPE html>
<html>
<head>
<script>
function randomiza(n) {
var ranNum = Math.round(Math.random()*n);
return ranNum;
}
function mod(dividendo,divisor) {
return Math.round(dividendo - (Math.floor(dividendo/divisor)*divisor));
}
function gerarCPF() {
comPontos = true; // TRUE para ativar e FALSE para desativar a pontuação.
var n = 9;
var n1 = randomiza(n);
var n2 = randomiza(n);
var n3 = randomiza(n);
var n4 = randomiza(n);
var n5 = randomiza(n);
var n6 = randomiza(n);
var n7 = randomiza(n);
var n8 = randomiza(n);
var n9 = randomiza(n);
var d1 = n9*2+n8*3+n7*4+n6*5+n5*6+n4*7+n3*8+n2*9+n1*10;
d1 = 11 - ( mod(d1,11) );
if (d1>=10) d1 = 0;
var d2 = d1*2+n9*3+n8*4+n7*5+n6*6+n5*7+n4*8+n3*9+n2*10+n1*11;
d2 = 11 - ( mod(d2,11) );
if (d2>=10) d2 = 0;
retorno = '';
if (comPontos) cpf = ''+n1+n2+n3+'.'+n4+n5+n6+'.'+n7+n8+n9+'-'+d1+d2;
else cpf = ''+n1+n2+n3+n4+n5+n6+n7+n8+n9+d1+d2;
//document.getElementById("demo").innerHTML = cpf
}
</script>
</head>
<body >
<input type="text" value="<script>document.write(cpf)</script>">
<input type="button" value="gerar" onclick("gerarCPF()")>
</body>
</html>