Free Online CNPJ Validator
Verify the structural validity of a Brazilian CNPJ business tax ID. Free online tool to validate CNPJ format. Secure and processed in your browser.
About this validator
This validator checks the mathematical consistency of a Brazilian CNPJ and helps reduce errors in forms, ERPs, and company sign-up flows.
Processing happens locally and does not confirm whether the company exists or is active in official records.
Best practices
- Strip all non-numeric characters before validation.
- Pair this check with an official registry lookup when you need authoritative data.
- Use real-time feedback to reduce rework while filling out forms.
Important notice
This tool validates only CNPJ structure. It does not confirm authenticity or business status.