Developer Tools

Free tools for developers working with CNPJ and CPF numbers. Perfect for testing and development.

CNPJ Validator

Check if a CNPJ is mathematically valid. Validates check digits instantly.

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CPF Validator

Check if a CPF is mathematically valid. Validates check digits instantly.

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CNPJ Generator

Generate valid CNPJ numbers for testing. Bulk generation up to 100 at once.

Generate

CPF Generator

Generate valid CPF numbers for testing. Bulk generation up to 100 at once.

Generate

Bulk Formatter

Format or unformat multiple CNPJ/CPF numbers at once. Auto-detects type and validates each entry.

Format now

Ferramentas CNAE

Consulta CNAE

Busque códigos CNAE por número ou descrição. Veja hierarquia completa.

Buscar CNAE

Verificador MEI

Descubra se seu CNAE pode ser MEI. Lista das 467 atividades permitidas em 2025.

Verificar MEI

Simples Nacional

Qual anexo do Simples? Calcule o Fator R e veja as aliquotas.

Calcular

Empresas por CNAE

Encontre empresas por setor de atividade. Lista completa por CNAE e regiao.

Ver empresas

Análise de Mercado

Descubra quantos concorrentes existem no seu setor por estado e cidade.

Analisar

Consulta Societária

Busca de Socios

Busque pessoas pelo nome e descubra em quais empresas participam do quadro societario.

Buscar socios

Grafo de Relacionamentos

Visualize conexoes entre empresas e socios em um grafo interativo.

Em breve

Free API

All tools are available via our free REST API. No authentication required.

Validate CNPJ


                    GET /api/tools/validate/cnpj/{cnpj}

Validate CPF


                    GET /api/tools/validate/cpf/{cpf}

Generate CNPJ


                    GET /api/tools/generate/cnpj?formatted=true&count=10

Generate CPF


                    GET /api/tools/generate/cpf?formatted=true&count=10

Bulk Format


                    POST /api/tools/format/bulk

                    {"values": ["12345678000195", "12345678901"]}

Auto-detect and Validate


                    GET /api/tools/detect/{value}

Why Use Our Developer Tools?

These free tools are designed for developers who need to work with Brazilian tax identification numbers. Whether you're building a registration form, testing an integration, or validating user input, our tools make it easy.

Use Cases

Form Testing: Generate valid CNPJs/CPFs to test your registration forms
Unit Tests: Use the API in your automated test suites
Data Validation: Validate user-submitted CNPJs/CPFs before processing
Data Cleanup: Format or unformat large lists of tax IDs

How CNPJ Validation Works

A CNPJ (Cadastro Nacional da Pessoa Juridica) has 14 digits. The last two digits are verification digits calculated using a modular arithmetic algorithm. Our validator checks if these digits are correct.

Note: A mathematically valid CNPJ doesn't guarantee the company exists. To check if a company is registered, search our database.

How CPF Validation Works

A CPF (Cadastro de Pessoa Fisica) has 11 digits. Similar to CNPJ, the last two digits are verification digits. Our validator ensures these digits follow the correct mathematical formula.