CPF Validator
Quickly check whether a Brazilian CPF number is valid according to the official rules of the Receita Federal (Brazil's federal tax authority). Type the number in the field below and click validate to get the result instantly.
What is a CPF?
The CPF (Cadastro de Pessoas Físicas) is the Brazilian individual taxpayer ID, issued by the Receita Federal. It has 11 digits and is used everywhere in Brazil: opening bank accounts, filing income tax returns, shopping online and signing up for services.
How does CPF validation work?
A CPF has 11 digits, and the last two are check digits. They are calculated from the other digits with a specific algorithm (weighted sums and modulo 11). Validation means checking the number's format, recalculating the check digits and comparing them with the ones provided.
How to use
- Enter the CPF — With or without dots and dash.
- Click Validate — The check runs automatically.
- See the result — Valid or invalid is shown instantly.
When to use this tool
- Before saving Brazilian customer data
- When testing form validation
- When integrating with Brazilian systems and APIs
- To catch typos
Note: This tool only checks the mathematical structure of the CPF. It does not verify whether the document exists or belongs to a real person.
Frequently asked questions
How do I know if a CPF is valid?
A CPF is valid when its two check digits match the calculation made on the first nine digits. The validator does that math automatically.
Does the validator check the CPF status with the Receita Federal?
No. The tool only checks whether the number is mathematically valid. To see whether a CPF is in good standing, use the Receita Federal website.
Do I need to type the CPF with dots and dash?
No. You can type the CPF with or without formatting (000.000.000-00 or 00000000000).
Why is 111.111.111-11 invalid?
CPFs with all identical digits pass the check digit calculation, but the Receita Federal never issues them, so they are considered invalid.