CPF validator
Check a Brazilian CPF's check digits with a step-by-step breakdown.
CPF
—
Type a CPF to validate it.
Recent
Nothing here yet.
About this tool
Validates a CPF against the official módulo 11 algorithm and shows the arithmetic: the weighted sum for each check digit, the remainder, and the digit that should have resulted. When a number fails, you can see precisely which digit is wrong.
Repeated-digit sequences such as 111.111.111-11 are rejected, as they are by the Receita Federal, even though they satisfy the check-digit arithmetic. Structural validity is not the same as registration status — a well-formed CPF may still be inactive or nonexistent.
How to use it
- 1Type or paste the CPF — punctuation is optional.
- 2Read the verdict, which updates as you type.
- 3Expand the breakdown to see how each check digit was derived.
Privacy
This tool runs entirely in your browser. Nothing you type or paste is sent to a server, and your local history is stored only on this device.
Related tools
- CNPJ validatorValidate numeric and new alphanumeric CNPJs, with the maths shown.
- JSON formatter & validatorPretty-print, minify and validate JSON with precise error positions.
- XML formatter & validatorIndent, minify and well-formedness-check XML documents.
- JWT decoder & validatorDecode header and payload, inspect claims and check expiry.