Credit Card Validator
Validate credit card numbers using the Luhn algorithm and detect the card brand from its IIN prefix. Supports Visa, Mastercard, American Express, Discover, Diners Club, and JCB. All data stays in your browser.
Features
- Luhn algorithm check
- Brand detection (Visa, MC, Amex, Discover, Diners, JCB)
- Expected CVV length per brand
- 100% client-side — no card data uploaded
Frequently Asked Questions
- Is my card number sent to a server?
- No. All validation happens locally in your browser. Your card number never leaves your device.
- Which brands are detected?
- Visa (starts with 4), Mastercard (5[1-5] or 2[2-7]), American Express (34 or 37), Discover (6011 or 65), Diners Club (30, 36, 38), and JCB (35).
- Does a valid Luhn mean the card is real?
- No. Luhn only checks structural integrity (no transposed digits). It does not confirm the account exists or is active — that requires an issuer check.