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Luhn Check Validator

Developer Utilities

Validate credit card numbers with the Luhn algorithm and detect the network such as Visa, Mastercard or Amex.

How to use

How the Luhn check works

Starting from the right, every second digit is doubled and its digits summed. If the total is divisible by ten the number passes. The tool also guesses the network from the leading digits.

  1. Type or paste the card number.
  2. The result and card type update as you type.
  3. Copy the normalised number if needed.

Frequently asked questions

Does a passing number mean the card is real?

No. The Luhn check only catches typing mistakes and random numbers. It says nothing about whether the card exists or is active.

Is my card number safe?

Yes, the check happens in your browser and the number is never transmitted.

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