Validate credit cards, IMEI numbers, and other identification numbers using the Luhn checksum algorithm.
⚠️ Checksum validator only. Passing Luhn does NOT verify that a card/ID is real, active, or belongs to you. It only detects accidental typos. Never use for authentication.
Last updated: March 2026 | Verification Tool
Only digits are processed
The Luhn algorithm (also known as the mod-10 algorithm) is a simple checksum formula used to validate credit card numbers, IMEI codes, and other identification numbers. It detects single-digit errors and some common transposition errors, making it useful for catching accidental data entry mistakes.
The algorithm works by doubling every second digit (from right to left), subtracting 9 from any resulting values greater than 9, and then summing all the digits. If the total is divisible by 10, the number is valid. While the Luhn algorithm is not a security measure, it's an industry standard for credential validation.
This algorithm is widely used by major credit card companies (Visa, MasterCard, American Express), and is also used for IMEI numbers on mobile phones, validation of ISBN numbers, and many other applications that need basic data integrity checking.
Let's validate: 49927398713
No, the Luhn algorithm is not a security measure. It only detects accidental errors, not deliberate fraud. It should never be used as the only validation method for sensitive data.
The algorithm detects all single-digit substitution errors and most transposition errors. However, it doesn't catch all transposition errors involving multiples of 10.
Credit card companies use Luhn as a quick check to catch data entry errors before processing transactions, reducing chargebacks from typos.
Yes! The Luhn algorithm is a simple mathematical checksum. You can validate numbers offline on any device that can do calculations.
Credit cards (Visa, Mastercard, Amex), IMEI numbers on phones, SIM card numbers, ISBNs, and many government ID numbers use Luhn validation.
Most major credit card companies use Luhn, but it's worth noting that some legacy systems or regional institutions might not. It's best to verify with your payment processor.
It's called mod-10 because the final validation step uses the modulo 10 operation (checking if the sum is divisible by 10).
Yes, but only for basic format validation. Never expose real card numbers online. Always use this tool for educational purposes or development/testing only.
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