What does this tool do?
The Credit Card Validator instantly checks whether a card number is format-valid using the Luhn algorithm (mod 10 checksum) and identifies the card brand from its prefix. It is handy for developers testing payment forms, anyone validating sample data, and curious users learning how card numbers are structured.
How to use it
- Choose the required options or length.
- Generate the secure result.
- Copy and store the result safely.
How it works
The tool processes your digits right to left, doubling every second digit; if a doubled value exceeds 9 it subtracts 9, then sums everything. If the total is divisible by 10, the number passes the Luhn check. It also reads the prefix to detect the brand: numbers starting with 4 are Visa, 51-55 or 2221-2720 Mastercard, 34/37 American Express, 6011/65 Discover, 30/36/38 Diners Club, and 35 JCB. Spaces are ignored automatically.
An important limitation
This is format validation only. It does not query a bank, confirm the card exists, or check whether it is active or has funds. A number that passes Luhn is mathematically consistent but not necessarily real. Test numbers such as 4532 0151 1283 0366 are perfect for exercising checkout flows. As a habit, avoid pasting your full real card number into any web tool, even though everything here runs locally in your browser.
Frequently asked questions
Does a valid result mean the card is real?
No. It only means the number passes the Luhn checksum and has a plausible length. It says nothing about whether the card exists, is active, or has a balance.
Which card brands are detected?
Visa, Mastercard, American Express, Discover, Diners Club, and JCB. The brand is inferred from the leading digits (the BIN prefix); if none match, it shows 'Unknown'.
Why is my number marked invalid?
Either it has fewer than 12 digits, you mistyped a digit, or it fails the Luhn checksum. Remove spaces and re-check each digit carefully.
Is Credit Card Validator free?
Yes. Credit Card Validator and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. Credit Card Validator works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.