Credit Card Validator
The Luhn algorithm catches typing mistakes in card numbers, and the first digits reveal the brand. Enter a number to check both instantly in your browser. Nothing is uploaded, so use test numbers only and never a real card.
Luhn check
—
Brand
—
Digits
0
Masked
—
Use only test numbers such as 4242 4242 4242 4242 when developing checkout forms.
How to use
- Type or paste a card number (spaces are ignored).
- The Luhn result, brand and masked number update live.
- Use test numbers only while building and testing payment forms.
Tips
- This checks the number's format only - a valid Luhn result does not mean the card is real or funded.
- Payment forms should validate again on the server; browser checks can be bypassed.
- Use the well-known test numbers from Stripe or PayPal docs while building.
- Mask stored or displayed card numbers and never log full numbers.
Note: A valid Luhn result only means the number is well formed — it does not mean the card exists or has funds. Never type a real card number into any website tool.