CNPJ Validator Online

CNPJ (Cadastro Nacional de Pessoa Jurídica) is a tax identification number assigned to companies and other organizations in Brazil.

To validate a CNPJ (Cadastro Nacional de Pessoa Jurídica), you can follow the following steps:

  1. Remove all non-numeric characters from the CNPJ, leaving only the digits.
  2. Check if the CNPJ has exactly 14 digits.
  3. Check if the CNPJ does not consist of repeated digits (e.g. 11.111.111/1111-11).
  4. Calculate the first CNPJ verifier digit using a multiplication and sum formula. Compare the calculated digit with the actual digit of the CNPJ.
  5. Calculate the second CNPJ verifier digit using a multiplication and sum formula. Compare the calculated digit with the actual digit of the CNPJ.
  6. If the calculated verifier digits match the actual digits of the CNPJ, the CNPJ is valid. Otherwise, the CNPJ is invalid.

In summary, CNPJ validation involves removing non-numeric characters, checking for length and repeated digits, and calculating and comparing verifier digits using multiplication and sum formulas.

Exemple em Javascript code:

function validateCNPJ(cnpj) {
    cnpj = cnpj.replace(/[^\d]+/g,'');
    if (cnpj.length !== 14) {
        return false;
    }
    if (/^(\d)\1+$/.test(cnpj)) {
        return false;
    }
    let sum = 0;
    let multiplier = 2;
    for (let i = 11; i >= 0; i--) {
        sum += cnpj.charAt(i) * multiplier;
        multiplier = (multiplier + 1) % 9 || 2;
    }
    const firstDigit = (sum % 11) < 2 ? 0 : 11 - (sum % 11);
    if (cnpj.charAt(12) != firstDigit) {
        return false;
    }
    sum = 0;
    multiplier = 2;
    for (let i = 12; i >= 0; i--) {
        sum += cnpj.charAt(i) * multiplier;
        multiplier = (multiplier + 1) % 9 || 2;
    }
    const secondDigit = (sum % 11) < 2 ? 0 : 11 - (sum % 11);
    if (cnpj.charAt(13) != secondDigit) {
        return false;
    }
    return true;
}