Real CNPJ check digit validation
The tool strips punctuation, calculates both CNPJ check digits, and shows formatted and digits-only output. This helps separate mask issues from true algorithm errors.
Generated CNPJs are useful for forms, QA, staging, and automated tests. They do not identify real companies and should not be used for fraud or impersonation.
Exports for test fixtures
Generate 1 to 200 CNPJs at once, set the branch code, and choose formatted or raw digits. Copy the list or download it for spreadsheets, fixtures, and scripts.
Processing happens in the browser whenever possible. Files and inputs do not need to be uploaded to the site server for the main workflow.
- Line-based TXT
- CSV with header
- JSON for API tests
Important limits
A mathematically valid CNPJ does not prove legal existence, status, or official registry data. This page validates only numeric structure and check digits.