How to validate CPF on client side with script?

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CPF Generator and Validator

To validate just use this line:

CPF.valida("123.456.789-00");

The lib already filters points and dashes.

View on Github

Example of use

/*!
*	Gerador e Validador de CPF v1.0.0
*	https://github.com/tiagoporto/gerador-validador-cpf
*	Copyright (c) 2014-2015 Tiago Porto (http://www.tiagoporto.com)
*	Released under the MIT license
*/
function CPF(){"user_strict";function r(r){for(var t=null,n=0;9>n;++n)t+=r.toString().charAt(n)*(10-n);var i=t%11;return i=2>i?0:11-i}function t(r){for(var t=null,n=0;10>n;++n)t+=r.toString().charAt(n)*(11-n);var i=t%11;return i=2>i?0:11-i}var n="CPF Inválido",i="CPF Válido";this.gera=function(){for(var n="",i=0;9>i;++i)n+=Math.floor(9*Math.random())+"";var o=r(n),a=n+"-"+o+t(n+""+o);return a},this.valida=function(o){for(var a=o.replace(/\D/g,""),u=a.substring(0,9),f=a.substring(9,11),v=0;10>v;v++)if(""+u+f==""+v+v+v+v+v+v+v+v+v+v+v)return n;var c=r(u),e=t(u+""+c);return f.toString()===c.toString()+e.toString()?i:n}}



   var CPF = new CPF();
   document.write(CPF.valida("123.456.789-00"));
   
   document.write("<br> Utilizando o proprio gerador da lib<br><br><br>");
   for(var i =0;i<40;i++) {
      var temp_cpf = CPF.gera();
      document.write(temp_cpf+" = "+CPF.valida(temp_cpf)+"<br>");
   }

$("#input").keypress(function(){
    $("#resposta").html(CPF.valida($(this).val()));
});

$("#input").blur(function(){
     $("#resposta").html(CPF.valida($(this).val()));
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script><inputtype="text" id="input" /><span id="resposta"></span><br><br><br><br>

I've assembled a JavaScript pseudo class to generate and validate CPF numbers, following the digits check rule. The source code can be found in GitHub:

• link

Here is an example usage:

var n = new CPF().generate();

if (new CPF().validate(n)) {
  alert('sucesso!');
}

If you need to create CPF numbers for testing, I made the same algorithm available on this static site:

• CPF Generator

Note that the numbers generated are valid, but are not real, unless a random number collision with a real number occurs.

To find out if a CPF number is real, only by consulting the Internal Revenue Service, but you must also provide the CPF holder's birth date:

• www.receita.fazenda.gov.br/aplicacoes/atcta/cpf/ConsultaPublica.asp

Finally, if there is a need for automatic validation of a large number of CPFs, I recommend the following Web Service:

• www.soawebservices.com.br

So far it was the cheapest I found, supports HTTPS and has reasonable availability (from time to time it suffers from timeout problems).

I did one in javascript using the federal recipe algorithm.

The method receives a string without points and dashes and returns a bool whether it is valid or not.

function VerificaCPF(strCpf) {

var soma;
var resto;
soma = 0;
if (strCpf == "00000000000") {
    return false;
}

for (i = 1; i <= 9; i++) {
    soma = soma + parseInt(strCpf.substring(i - 1, i)) * (11 - i);
}

resto = soma % 11;

if (resto == 10 || resto == 11 || resto < 2) {
    resto = 0;
} else {
    resto = 11 - resto;
}

if (resto != parseInt(strCpf.substring(9, 10))) {
    return false;
}

soma = 0;

for (i = 1; i <= 10; i++) {
    soma = soma + parseInt(strCpf.substring(i - 1, i)) * (12 - i);
}
resto = soma % 11;

if (resto == 10 || resto == 11 || resto < 2) {
    resto = 0;
} else {
    resto = 11 - resto;
}

if (resto != parseInt(strCpf.substring(10, 11))) {
    return false;
}

return true;
}

I've adapted the response script from @AlbertBitencourt .

Removing the part that considers 10 and 11 as 0 , since apparently this validation does not exist.

function cpf(cpf){
    cpf = cpf.replace(/\D/g, '');
    if(cpf.toString().length != 11 || /^(\d){10}$/.test(cpf)) return false;
    var result = true;
    [9,10].forEach(function(j){
        var soma = 0, r;
        cpf.split(/(?=)/).splice(0,j).forEach(function(e, i){
            soma += parseInt(e) * ((j+2)-(i+1));
        });
        r = soma % 11;
        r = (r <2)?0:11-r;
        if(r != cpf.substring(j, j+1)) result = false;
    });
    return result;
}

console.log('11111111111', cpf('11111111111'));
console.log('82312321312', cpf('82312321312'));
console.log('825.566.405-02', cpf('825.566.405-02'));
console.log('875.189.681-85', cpf('875.189.681-85'));
console.log('875.189.681-86', cpf('875.189.681-86'));
console.log('640.422.216-70', cpf('640.422.216-70'));

Related Links

Validating and Calculating the Control Digit of a CPF
Formula to generate valid CPF's