CPF and CNPJ Generator and Validator for Testing (Brazil)

Developers and testers need CPF and CNPJ numbers that pass validation to test forms, sign-ups and integrations without using real people's data. This tool generates fictitious numbers with the correct check digits and also validates numbers you type in. The CPF (Cadastro de Pessoas Físicas) is the Brazilian individual taxpayer registry number, and the CNPJ (Cadastro Nacional da Pessoa Jurídica) is the national registry number for companies.

Use it only in test environments. Generating documents to defraud registrations is a crime.

A CPF has 9 base digits and 2 check digits. For the first one, multiply the 9 digits by weights from 10 down to 2, add them up, multiply by 10 and take the remainder of the division by 11 (if it is 10, the digit is 0). For the second one, repeat the process with the 10 digits and weights from 11 down to 2.

A CNPJ has 12 base characters (8 for the root and 4 for the branch, e.g. 0001) and 2 check digits. The weights are 5,4,3,2,9,8,7,6,5,4,3,2 for the first digit and 6,5,4,3,2,9,8,7,6,5,4,3,2 for the second. If the remainder of the division by 11 is less than 2, the digit is 0; otherwise, it is 11 minus the remainder.

Starting in July 2026, new CNPJs may contain letters as well as numbers in the first 12 positions. The check digits are calculated the same way, using the ASCII value of the character minus 48 (A = 17, B = 18 and so on). The “Alphanumeric CNPJ” option generates numbers in this format.

A CPF has 11 digits in the format XXX.XXX.XXX-DD: the first 8 are the base number, the 9th digit indicates the fiscal region where the record originated, and the last 2 are the check digits.

The generator draws the base number without choosing a region: the 9th digit is random.

A CNPJ has 14 positions in the format XX.XXX.XXX/XXXX-DD: 8 for the root (the company), 4 for the order number (the establishment; 0001 is the head office) and 2 check digits. In the alphanumeric CNPJ, the first 12 positions can hold letters and numbers, and the last 2 digits remain numeric.

The algorithm used by this page's validator, in JavaScript:

function cpfValido(cpf) {
  const n = cpf.replace(/\D/g, '');
  if (n.length !== 11 || /^(\d)\1{10}$/.test(n)) return false;
  const dv = (base) => {
    let soma = 0;
    for (let i = 0; i < base.length; i++) soma += Number(base[i]) * (base.length + 1 - i);
    const r = (soma * 10) % 11;
    return r === 10 ? 0 : r;
  };
  return dv(n.slice(0, 9)) === Number(n[9]) && dv(n.slice(0, 10)) === Number(n[10]);
}

For example, cpfValido('529.982.247-25') returns true. Validate on the server as well, not only in the browser.

• Never in production: use the numbers only in test and staging environments.
• Fictitious data: the CPF is personal data protected by the LGPD (Brazil's General Data Protection Law); generating numbers avoids using real people's data in test databases.
• Store without the mask: keep only the digits and apply the mask when displaying.
• Test the limits: include invalid cases, such as repeated sequences (111.111.111-11) and a wrong check digit.

Need passwords for your test users? Use the password generator. To set up environment variables, there is the Env Converter, and for a quick calculation, the online calculator.