CNPJ Generator

The CNPJ Generator creates mathematically valid CNPJ numbers — with correct check digits — for exclusive use in software development and testing. Applications that process company data need to validate CNPJs in forms, integrations, and registration flows, and for that you need algorithm-valid numbers without resorting to real existing companies' data.

To use it, choose the desired quantity (up to 100 at a time) and select whether you prefer the masked format (XX.XXX.XXX/XXXX-XX) or digits only. Each CNPJ can be copied individually or all at once. The generation algorithm follows the same check digit calculation rules used by the Brazilian Federal Revenue Service.

As with CPF generation, it is essential to understand that these numbers are valid only mathematically. They do not correspond to any real company registered in the CNPJ database and must not be used outside of software testing contexts. Using a fictitious CNPJ in documents, contracts, or any official process constitutes improper use.

Legitimate use cases: populating development environments with fictitious company data, testing CNPJ masks and validators in forms, building fixtures for integration tests, and verifying the behavior of systems that consume legal entity data. All processing happens in the browser, with no data transmitted to external servers.