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Luhn / Card Validator

Check a number with the Luhn algorithm and detect the card brand by prefix.

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Files are processed in your browser, never uploaded. The site downloads code and assets to run the tools. No accounts or trackers.

Use Download to save this tool as one HTML file for offline use.

number

About this tool

Validate a number with the Luhn check digit algorithm and guess the card brand, entirely in your browser.

Does a valid result mean a real card?

No. The Luhn check only confirms the digits form a valid checksum; it does not mean the account exists or is active.

Which brands are detected?

Visa, Mastercard, American Express and Discover, recognised by their number prefixes and lengths.