CPF Validator
Validate Brazilian CPF numbers instantly using the official algorithm. Useful for testing document validation in applications. No data sent to servers.
How does CPF validation work?
Validation follows the check-digit algorithm of the Brazilian Federal Revenue (Receita Federal). A CPF has 11 digits: the first 9 are the base number and the last 2 are control digits, calculated by weighted multiplication with modulo 11.
A CPF is considered invalid if the check digits do not match the calculation, or if it is a repeated sequence — such as "111.111.111-11" — which passes the formatting mask but fails the mathematical algorithm.
The check runs entirely in your browser. No CPF entered here is sent to servers or recorded.
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