@fnando/cnpj

CNPJ

This package does some CNPJ magic. It allows you to create, validate and format CNPJ documents.

[!NOTE]

This library already supports the new alphanumeric CNPJ algorithm that will be available starting July 2026. For more information, see https://www.gov.br/receitafederal/pt-br/acesso-a-informacao/acoes-e-programas/programas-e-atividades/cnpj-alfanumerico.

HINT: Check out the CPF counter part available at https://github.com/fnando/cpf.

Installation

This lib is available as a NPM package. To install it, use the following command:

npm install @fnando/cnpj --save

If you're using Yarn (and you should):

yarn add @fnando/cnpj

Usage

// Node.js-specific
const cnpj = require("@fnando/cnpj/commonjs");

// @import
import * as cnpj from "@fnando/cnpj"; // import the whole library
import { isValid as isValidCnpj } from "@fnando/cnpj"; // import just one function

// import via <script>; the lib will available as window.CNPJ
// <script src="cnpj.js"></script>

cnpj.isValid("41.381.074/6738-65");
//=> true

cnpj.isValid("41381074673865");
//=> true

cnpj.strip("41.381.074/6738-65");
//=> 41381074673865

cnpj.format("41381074673865");
//=> 41.381.074/6738-65

cnpj.generate(true); // generate formatted number
//=> 54.385.406/3140-07

cnpj.generate(); // generate unformatted number
//=> 07033324230766

On the web, without transformation, just use web/cnpj.min.js.

Strict Validation

By default, validations will strip any characters you provide. This means that the following is valid, because only numbers will be considered:

cnpj.isValid("41#381#074-----6738\n\n65");
//=> true

cnpj.strip("41#381#074-----6738\n\n65");
//=> 41381074673865

If you want to strict validate strings, use the following signature:

cnpj.isValid(number, strict);

The same example would now return false:

cnpj.isValid("41#381#074-----6738\n\n65", true);
//=> false