ToolVaults

Credit Card Number Validator — Luhn Check + Brand Detection

Validate credit card numbers with the Luhn algorithm and detect the brand: Visa, Mastercard, American Express, Discover, JCB, Diners Club, UnionPay, and Maestro. Runs entirely in your browser.

Runs 100% in your browser — nothing is uploaded.

✓ Valid structure
Visa
  • Formatted: 4532 0151 1283 0366
  • Length: 16
  • Luhn checksum: ✓ pass
Structure only. This checks the Luhn algorithm and card-brand pattern — it does NOT confirm the card exists, has funds, or belongs to anyone. Never use this for actual authorization; always use a real payment processor.
Test numbers (Stripe test set, non-functional)

Frequently asked

Does this authorize a real card?

No. It only checks structural validity — brand pattern, length, and Luhn checksum. It cannot tell you whether a card is active, has funds, or belongs to anyone. Never use this for actual payment authorization; always go through a real payment processor.

Is my card number sent anywhere?

No. Everything runs in your browser — nothing is uploaded, logged, or transmitted. You can pull the network tab and watch: no requests are made.

Which brands are detected?

Visa, Mastercard (including 2-series BINs), American Express, Discover, JCB, Diners Club, UnionPay, and Maestro. Each has its own valid length ranges checked in addition to the Luhn checksum.

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