CPF Validator
Quickly check whether a Brazilian CPF (individual tax ID) is structurally valid. The check-digit verification runs in real time in your browser.
Responsible use
How to verify the result
A useful tool should let you verify its output. Start with a small test, keep the original and only then use the result in production. The scenario below helps catch problems before you copy, download or share anything.
Practical check
Use test numbers only. A valid result confirms format and check digits, not that a taxpayer record exists or is active.
What this tool does not replace
The tool checks structure and digits but not ownership, registry status or authenticity. Use the official authority for that and avoid sharing real documents unnecessarily.
Data handling
Primary content is processed in your browser and is not sent to the UseHubTools server. Local data may remain in browser storage until you clear it.
Content reviewed on August 11, 2026.
How the CPF is validated
A CPF has 11 digits, the last 2 being check digits. We compute them with the Module 11 algorithm and compare with the input.
What validation does not do
It is a structural check: it confirms the number is mathematically valid, not whether it is active or belongs to someone. Use official Receita Federal channels for that.
How to use
Type the CPF with or without dots and dash — the tool formats it for you and validates the check digits in real time as you type. Ideal to verify forms, customer records and spreadsheets, avoiding typos before saving the data.
Frequently asked questions
Does a valid CPF mean it exists?
Not necessarily — it means the check digits are correct.
Is data stored?
No, everything runs in your browser.
Does it accept formatted CPF?
Yes, we format it automatically as you type.
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