Credit Card Validator — Check Card Numbers with Luhn Algorithm
Validate credit card numbers instantly. Detects card type. 100% private.
💡 Enter digits only - spaces will be added automatically
Supported Card Types:
💳 Visa
💳 Mastercard
💳 American Express
💳 Discover
💳 Diners Club
💳 JCB
💳 UnionPay
💳 Maestro
🔒 Privacy & Security
- All validation happens in your browser (client-side JavaScript)
- No card numbers are sent to any server or stored anywhere
- This tool only validates format - it does NOT authorize payments
- Never share your real card numbers with untrusted websites
- Use for development, testing, and educational purposes only
About Credit Card Validator
Validate credit card numbers using the industry-standard Luhn algorithm (mod-10 checksum). Instantly check if a card number is mathematically valid and detect the card type (Visa, Mastercard, Amex, etc.).
Perfect for developers testing payment integrations, form validation, or anyone who needs to quickly verify a card number format. All processing happens locally in your browser - no data is transmitted or stored.
How to Use Credit Card Validator
- Enter or paste a credit card number (digits only).
- The tool automatically formats and validates as you type.
- View the card type (Visa, Mastercard, etc.) if detected.
- See validation status: Valid ✓ or Invalid ✗.
- Use for testing, development, or form validation.
Key Features
Luhn algorithm validation (mod-10)
Auto-detect card type from number
Supports all major card types
Real-time validation as you type
Auto-formatting with spaces
Clear error messages
Copy formatted number
Batch validation mode
100% client-side processing
No data stored or transmitted
Frequently Asked Questions
How does the Luhn algorithm work?
The Luhn algorithm (also called mod-10) validates card numbers by calculating a checksum. It doubles every second digit from right to left, sums all digits, and checks if the total is divisible by 10.
Is it safe to enter my card number?
Yes! All validation happens 100% in your browser using JavaScript. No card numbers are sent to any server or stored anywhere. The tool is completely private and secure.
What card types are supported?
The validator detects and validates Visa, Mastercard, American Express, Discover, Diners Club, JCB, UnionPay, and Maestro cards based on their number patterns and length.
Why does my card fail validation?
If a real card fails validation, double-check for typos. The Luhn algorithm is highly accurate but requires the exact number. Also ensure there are no spaces or special characters.
Can this validator authorize payments?
No! This tool only validates the format and checksum of card numbers. It does NOT verify if a card is active, has sufficient funds, or authorize any transactions.