Credit Card / Luhn Validator

Type or paste a card number. We'll check the Luhn (mod-10) checksum, look up the issuer from the leading digits (Visa, Mastercard, Amex, Discover, JCB, Diners, Maestro, UnionPay, Mir, Verve), and tell you whether the number is structurally valid. Bulk mode processes one PAN per line. Nothing is uploaded.

Test card presets

Spaces and dashes are stripped automatically. After 5 seconds of inactivity the number is masked to •••• •••• •••• 1234 so a casual passer-by can't read it off your screen.

Result

Luhn check
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Issuer
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Digits
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Check digit
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Formatted —
Paste a card number above (or pick a preset) to see the result here.
one PAN per line · up to 500
0 valid 0 invalid 0 rows

How Luhn validation works
  • The Luhn algorithm (a.k.a. mod-10) is a single-digit checksum appended to every PAN on every Visa, Mastercard, Amex, Discover, JCB, Diners, Maestro, UnionPay, Mir, and Verve card.
  • Walk the digits from right to left. On every second digit, double the value; subtract 9 if the doubled value exceeds 9. Sum everything. The total must leave remainder 0 when divided by 10.
  • This validator confirms structural correctness only. It does not verify that the card belongs to a real account — only the card network can do that.
  • Brand detection uses the leading 1–6 digits (the IIN). Anything outside the 10-network registry shows as Unknown network, never a guess.
  • After 5 seconds of inactivity the input is masked so a shoulder-surfer can't read the PAN off your screen. Click Show digits to reveal it again.
  • Nothing is uploaded. The whole thing runs in your browser, including the bulk-mode TSV export.