What does the CNPJ generator do?

It creates 14-digit sequences that follow the official CNPJ check algorithm. The numbers are mathematically valid in format and check digits, but don't belong to any real company — they are only useful for testing systems that validate CNPJs.

Do the generated CNPJs belong to any company?

No. The tool only computes the check digits correctly, without consulting any database. There is no link between the generated numbers and real companies registered with the Receita Federal.

Can I use these CNPJs to issue invoices or for real registrations?

No. Using generated CNPJs in real registrations, NF-e (electronic invoices), or to impersonate an existing company is identity fraud and may constitute a crime. The tool is intended exclusively for software testing and mask validation.

How does the CNPJ algorithm work?

The CNPJ has 14 digits: 8 for the company root, 4 for the branch number, and 2 check digits. The first 12 are generated randomly (with the branch fixed at 0001 when 'headquarters' is enabled) and the last 2 are computed by applying modulo 11 over the previous ones with specific weights.

What is the alphanumeric CNPJ?

Since July 2026 Brazil's Federal Revenue issues CNPJs with letters and numbers in the first 12 positions; the 2 check digits remain numeric. The calculation still uses modulo 11, with each character's ASCII code minus 48 (0 to 9 are worth 0 to 9, A is 17, B is 18 and so on). Existing numeric CNPJs remain valid.

What's the difference between headquarters and branch?

Digits 9 to 12 of the CNPJ indicate the company unit number. The value 0001 is always the headquarters; values like 0002, 0003, and so on represent branches. The root (first 8 digits) is the same for all units of the same company.

Are the generated CNPJs saved on any server?

No. All generation happens locally in your browser. No generated CNPJ is sent to ToolboxHub servers.

Free Online CNPJ Generator: Valid CNPJs for Testing

About the CNPJ Generator

Generate valid CNPJs for software testing, with or without masking and choosing between headquarters (0001) or random branch. The numbers follow the official check-digit algorithm, so they pass any format validation — but they don't correspond to real companies. Use only for development purposes.

How to generate CNPJs in 3 steps

1Choose the quantity (1 to 100).
2Choose Headquarters or Random branch, the numeric or alphanumeric format and whether you want the mask.
3Copy the list with Copy all or one number at a time; Generate again draws new ones.

CNPJ structure

The CNPJ has 14 characters in three blocks. Since July 2026 the first 12 also accept letters; the example is the alphanumeric CNPJ 12.ABC.345/01DE-35.

Position	Example	Meaning
1–8	12.ABC.345	Company root (base CNPJ)
9–12	01DE	Branch number (0001 = headquarters)
13–14	35	Check digits

CNPJ Generator